diff --git a/src/base/errors.c b/src/base/errors.c
index e3f61a2..5adc0ee 100644
--- a/src/base/errors.c
+++ b/src/base/errors.c
@@ -12,6 +12,7 @@ char* errname(ErrorId err){
         case ERR_NULLPTR: return "ERR_NULLPTR";
         case ERR_ENDOFSTR: return "ERR_ENDOFSTR";
         case ERR_KEYNOTFOUND: return "ERR_KEYNOTFOUND";
+        case ERR_FORMAT: return "ERR_FORMAT";
         default: return "UNKNOWN_ERROR";
     }
 }
diff --git a/src/base/kprint/README.md b/src/base/kprint/README.md
index 6961b00..354d3bd 100644
--- a/src/base/kprint/README.md
+++ b/src/base/kprint/README.md
@@ -10,7 +10,7 @@ I don't really like printf function (and its variants), so i made safer and more
 ## how to use it:
 + **format construction:**  
     ```
-    kprint_format fmt= kprint_fgColor | kprint_fbgColor | kprint_fdataFmt | flags | ktId;
+    kprint_format fmt= kprint_fgColor | kprint_bgColor | kprint_fdataFmt | flags | ktId;
     ```
     [more about `kprint_format`](kprint_format.md)
     + fgColor and bgColor can be set to change console output color
diff --git a/src/base/kprint/kprint.c b/src/base/kprint/kprint.c
index f099b69..744fc74 100644
--- a/src/base/kprint/kprint.c
+++ b/src/base/kprint/kprint.c
@@ -1,29 +1,37 @@
-/* #include "../base.h"
+#include "../base.h"
 #include "../../String/StringBuilder.h"
 
-Maybe __next_toString(kprint_format format, void* object){
-    // detecting type
-    if(!format.typeId) switch((kprint_dataFormat)((uint32)0 | format.dataFmt)){
+ktId __typeFromFormat(kprint_format f){
+    ktId typeId=kprint_format_ktId(f);
+    if(typeId) 
+        return typeId;
+    switch(kprint_format_dataFormat(f)){
         case kprint_fmtInt:
         case kprint_fmtHex:
         case kprint_fmtBin: 
-            format.typeId=ktId_Int64; break;
+            return ktId_Int64;
         case kprint_fmtUInt:
-            format.typeId=ktId_UInt64; break;
+            return ktId_UInt64; 
         case kprint_fmtFloat:
-            format.typeId=ktId_Float64; break;
+            return ktId_Float64; 
         case kprint_fmtChar:
-            format.typeId=ktId_Char; break;
+            return ktId_Char; 
         case kprint_fmtString:
-            format.typeId=ktId_CharPtr; break;
+            return ktId_CharPtr; 
         default: 
-            safethrow("typeId is not set, can't autodetect type",;);
+            return -1;
     }
-    ktDescriptor typeDesc=ktDescriptor_get(format.typeId);
+}
+
+Maybe __next_toString(kprint_format f, void* object){
+    // detecting type
+    ktId typeId=__typeFromFormat(f);
+    if(typeId==-1)
+        safethrow("typeId is not set, can't autodetect type",;);
+    ktDescriptor typeDesc=ktDescriptor_get(typeId);
     if(!typeDesc.toString)
         safethrow("type descriptor doesnt have toString() func",;);
-    try(typeDesc.toString(object, &format), mStr,;);
-    return SUCCESS(mStr.value);
+    return SUCCESS(UniHeap(ktId_CharPtr, typeDesc.toString(object, f)));
 }
 
 Maybe __ksprint(uint8 n, kprint_format* formats, void** objects){
@@ -43,6 +51,7 @@ Maybe __kfprint(FILE* file, uint8 n, kprint_format* formats, void** objects){
             safethrow("can't write string to file", Unitype_free(maybeStr.value));
         Unitype_free(maybeStr.value);
     }
+    fflush(file);
     return MaybeNull;
 }
 
@@ -50,24 +59,94 @@ void __kprint(uint8 n, kprint_format* formats, void** objects){
     for(uint8 i=0; i<n; i++){
         kprint_format fmt=formats[i];
         kprint_setColor(fmt);
-         tryLast(__next_toString(fmt, objects[i]),maybeStr);
+        tryLast(__next_toString(fmt, objects[i]),maybeStr);
         if(fputs(maybeStr.value.VoidPtr, stdout)==EOF)\
             throw("can't write string to stdout");
             //, Unitype_free(maybeStr.value)
         Unitype_free(maybeStr.value);
     }
+    fflush(stdout);
 }
 
+#if defined(_WIN32)|| defined(_WIN64)
+#include <windows.h>
+#define FOREGROUND_YELLOW FOREGROUND_GREEN | FOREGROUND_RED
+
+DWORD kprint_fgColor_toWin(kprint_fgColor f){ 
+    //printf("fg: %x\n", f);
+    switch(f){
+        case kprint_fgBlack: return 0;
+        case kprint_fgDarkRed: return FOREGROUND_RED;
+        case kprint_fgDarkGreen: return FOREGROUND_GREEN;
+        case kprint_fgDarkYellow: return FOREGROUND_GREEN | FOREGROUND_RED;
+        case kprint_fgDarkBlue: return FOREGROUND_BLUE;
+        case kprint_fgDarkMagneta: return FOREGROUND_RED | FOREGROUND_BLUE;
+        case kprint_fgDarkCyan: return FOREGROUND_BLUE | FOREGROUND_GREEN;
+        case kprint_fgGray: return FOREGROUND_BLUE | FOREGROUND_GREEN | FOREGROUND_RED;
+        case kprint_fgDarkGray: return FOREGROUND_INTENSITY;
+        case kprint_fgRed: return FOREGROUND_RED | FOREGROUND_INTENSITY;
+        case kprint_fgGreen: return FOREGROUND_GREEN | FOREGROUND_INTENSITY;
+        case kprint_fgYellow: return FOREGROUND_GREEN | FOREGROUND_RED | FOREGROUND_INTENSITY;
+        case kprint_fgBlue: return FOREGROUND_BLUE | FOREGROUND_INTENSITY;
+        case kprint_fgMagneta: return FOREGROUND_BLUE | FOREGROUND_RED | FOREGROUND_INTENSITY;
+        case kprint_fgCyan: return FOREGROUND_BLUE | FOREGROUND_GREEN | FOREGROUND_INTENSITY;
+        case kprint_fgWhite: return FOREGROUND_RED | FOREGROUND_BLUE | FOREGROUND_GREEN | FOREGROUND_INTENSITY;
+        default: throw(ERR_FORMAT);
+    }
+}
+
+DWORD kprint_bgColor_toWin(kprint_bgColor f){ 
+    //printf("bg: %x\n", f);
+    switch(f){
+        case kprint_bgBlack: return 0;
+        case kprint_bgDarkRed: return BACKGROUND_RED;
+        case kprint_bgDarkGreen: return BACKGROUND_GREEN;
+        case kprint_bgDarkYellow: return BACKGROUND_GREEN | BACKGROUND_RED;
+        case kprint_bgDarkBlue: return BACKGROUND_BLUE;
+        case kprint_bgDarkMagneta: return BACKGROUND_RED | BACKGROUND_BLUE;
+        case kprint_bgDarkCyan: return BACKGROUND_BLUE | BACKGROUND_GREEN;
+        case kprint_bgGray: return BACKGROUND_BLUE | BACKGROUND_GREEN | BACKGROUND_RED;
+        case kprint_bgDarkGray: return BACKGROUND_INTENSITY;
+        case kprint_bgRed: return BACKGROUND_RED | BACKGROUND_INTENSITY;
+        case kprint_bgGreen: return BACKGROUND_GREEN | BACKGROUND_INTENSITY;
+        case kprint_bgYellow: return BACKGROUND_GREEN | BACKGROUND_RED | BACKGROUND_INTENSITY;
+        case kprint_bgBlue: return BACKGROUND_BLUE | BACKGROUND_INTENSITY;
+        case kprint_bgMagneta: return BACKGROUND_BLUE | BACKGROUND_RED | BACKGROUND_INTENSITY;
+        case kprint_bgCyan: return BACKGROUND_BLUE | BACKGROUND_GREEN | BACKGROUND_INTENSITY;
+        case kprint_bgWhite: return BACKGROUND_RED | BACKGROUND_BLUE | BACKGROUND_GREEN | BACKGROUND_INTENSITY;
+        default: throw(ERR_FORMAT);
+    }
+}
 
 void kprint_setColor(kprint_format f){
-    if(!f.bgColorChanged | !f.fgColorChanged)
+    DWORD color=0;
+    if(!kprint_format_fgColorChanged(f) & !kprint_format_bgColorChanged(f))
         return;
+    if(kprint_format_fgColorChanged(f))
+        color+=kprint_fgColor_toWin(kprint_format_fgColor(f));
+    if(kprint_format_bgColorChanged(f))
+        color+=kprint_bgColor_toWin(kprint_format_bgColor(f));
+    HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
+    SetConsoleTextAttribute(hConsole, color);
 }
+#else
+void kprint_setColor(kprint_format f){
+    if(kprint_format_fgColorChanged(f)){
+        uint8 fg=(f&0x0f000000)>>24;
+        if(fg<8) fg+=30;
+        else fg+=90-8;
+        printf("\e[%um", fg);
+    }
+    if(kprint_format_bgColorChanged(f)){
+        uint8 bg=(f&0x00f00000)>>20;
+        if(bg<8) bg+=40;
+        else bg+=100-8;
+        printf("\e[%um", bg);
+    }
+}
+#endif
 
-
-
-
-Maybe ksprint_ar(uint32 count, kprint_format format, ktId typeId, void* array){
+/* Maybe ksprint_ar(uint32 count, kprint_format format, ktId typeId, void* array){
     ktDescriptor typeDesc=ktDescriptor_get(format.typeId);
     if(!typeDesc.toString)
         safethrow("type descriptor doesnt have toString() func",;);
@@ -75,11 +154,11 @@ Maybe ksprint_ar(uint32 count, kprint_format format, ktId typeId, void* array){
     StringBuilder_append_char(strb, '[');
     for (uint16 e=1; e<count; e++){
         StringBuilder_append_char(strb, ' ');
-        try(typeDesc.toString(array+typeDesc.size*e, &format), estr, StringBuilder_free(strb));
-        StringBuilder_append_cptr(strb, estr.value.VoidPtr);
+        char* elStr=typeDesc.toString(array+typeDesc.size*e, &format);
+        StringBuilder_append_cptr(strb, elStr);
         StringBuilder_append_char(strb, ',');
     }
     StringBuilder_rmchar(strb);
     StringBuilder_append_char(strb, ' ');
     StringBuilder_append_char(strb, ']');
-} */
\ No newline at end of file
+} */
diff --git a/src/base/kprint/kprint.h b/src/base/kprint/kprint.h
index 5668638..3acdd2f 100644
--- a/src/base/kprint/kprint.h
+++ b/src/base/kprint/kprint.h
@@ -48,13 +48,13 @@ extern "C" {
     __kprint_argsToObjects32(ARGS))
 
 
-Maybe __ksprint(uint8 n, int32* formats, void** objects);
+Maybe __ksprint(uint8 n, kprint_format* formats, void** objects);
 #define ksprint(ARGS...) __ksprint(count_args(ARGS), __kprint_argsToArrs(count_args(ARGS),ARGS, __32zeroes))
 
-Maybe __kfprint(FILE* fd, uint8 n, int32* formats, void** objects);
+Maybe __kfprint(FILE* fd, uint8 n, kprint_format* formats, void** objects);
 #define kfprint(FD, ARGS...) __kfprint(FD, count_args(ARGS), __kprint_argsToArrs(count_args(ARGS),ARGS, __32zeroes))
 
-void __kprint(uint8 n, int32* formats, void** objects);
+void __kprint(uint8 n, kprint_format* formats, void** objects);
 #define kprint(ARGS...) __kprint(count_args(ARGS), __kprint_argsToArrs(count_args(ARGS),ARGS, __32zeroes))
 
 // can take (bgColor | fgColor) 
diff --git a/src/base/kprint/kprint_format.h b/src/base/kprint/kprint_format.h
index 6bbce44..9568ac9 100644
--- a/src/base/kprint/kprint_format.h
+++ b/src/base/kprint/kprint_format.h
@@ -31,19 +31,17 @@ typedef enum kprint_dataFormat{
     kprint_fmtUppercase=0x10000000
 } kprint_dataFormat;
 
-typedef union {
-    int32 i32;
-    struct { 
-        unsigned char fgColorChanged : 1;
-        unsigned char bgColorChanged : 1;
-        unsigned char withPrefix : 1;
-        unsigned char uppercase : 1;
-        unsigned char fgColor : 4;
-        unsigned char bgColor : 4;
-        unsigned char dataFmt : 4;
-        ktId typeId;
-    };
-} kprint_format;
+typedef uint32 kprint_format;
+
+#define kprint_format_fgColorChanged(FMT) (FMT&0x80000000)
+#define kprint_format_bgColorChanged(FMT) (FMT&0x40000000)
+#define kprint_format_withPrefix(FMT) (FMT&kprint_fmtWithPrefix)
+#define kprint_format_withPostfix(FMT) (FMT&kprint_fmtWithPostfix)
+#define kprint_format_uppercase(FMT) (FMT&kprint_fmtUppercase)
+#define kprint_format_fgColor(FMT) (kprint_fgColor)(FMT&0x8f000000)
+#define kprint_format_bgColor(FMT) (kprint_bgColor)(FMT&0x40f00000)
+#define kprint_format_dataFormat(FMT) (kprint_dataFormat)(FMT&0x000f0000)
+#define kprint_format_ktId(FMT) (kprint_dataFormat)(FMT&0x0000ffff)
 
 #if __cplusplus
 }
diff --git a/src/base/type_system/base_toString.c b/src/base/type_system/base_toString.c
index 7b47bb1..2d49c9c 100644
--- a/src/base/type_system/base_toString.c
+++ b/src/base/type_system/base_toString.c
@@ -52,7 +52,7 @@ char* toString_float(float64 n, bool withPostfix, bool uppercase){
 }
 
 char* toString_bin(char* bytes, uint32 size, bool withPrefix){
-    char* str=malloc(size*8+1);
+    char* str=malloc(size*8 + (withPrefix?2:0) +1);
     uint32 cn=0;
     if(withPrefix){
         str[cn++]='0';
@@ -80,7 +80,7 @@ char _4bitsHex(uint8 u, bool uppercase){
 }
 
 char* toString_hex(char* bytes, uint32 size, bool withPrefix, bool uppercase){
-    char* str=malloc(size*2);
+    char* str=malloc(size*2 + (withPrefix?2:0) + 1);
     uint32 cn=0;
     if(withPrefix){
         str[cn++]='0';
@@ -96,18 +96,17 @@ char* toString_hex(char* bytes, uint32 size, bool withPrefix, bool uppercase){
 }
 
 
-#define __toString_int_def(BITS) char* __toString_int##BITS(void* _n, int32 _f){\
-    kprint_format f=*(kprint_format*)&_f;\
-    switch(f.dataFmt | (uint32)0){\
-        case kprint_fmtInt:\
+#define __toString_int_def(BITS) char* __toString_int##BITS(void* _n, uint32 f){\
+    switch(kprint_format_dataFormat(f)){\
+        case kprint_fmtInt: ;\
             int##BITS n=*(int##BITS*)_n;\
             return toString_int(n);\
         case kprint_fmtBin:\
-            return toString_bin(_n, BITS/8, f.withPrefix);\
+            return toString_bin(_n, BITS/8, kprint_format_withPrefix(f));\
         case kprint_fmtHex:\
-            return toString_hex(_n, BITS/8, f.withPrefix, f.uppercase);\
+            return toString_hex(_n, BITS/8, kprint_format_withPrefix(f), kprint_format_uppercase(f));\
         default:\
-            printf("\n%u\n", f.dataFmt);\
+            printf("\n%u\n", kprint_format_dataFormat(f));\
             throw(ERR_FORMAT);\
             return NULL;\
     }\
@@ -117,18 +116,17 @@ __toString_int_def(16)
 __toString_int_def(32)
 __toString_int_def(64)
 
-#define __toString_uint_def(BITS) char* __toString_uint##BITS(void* _n, int32 _f){\
-    kprint_format f=*(kprint_format*)&_f;\
-    switch(f.dataFmt | (uint32)0){\
-        case kprint_fmtUInt:\
+#define __toString_uint_def(BITS) char* __toString_uint##BITS(void* _n, uint32 f){\
+    switch(kprint_format_dataFormat(f)){\
+        case kprint_fmtUInt: ;\
             uint##BITS n=*(uint##BITS*)_n;\
-            return toString_uint(n, f.withPrefix, f.uppercase);\
+            return toString_uint(n, kprint_format_withPostfix(f), kprint_format_uppercase(f));\
         case kprint_fmtBin:\
-            return toString_bin(_n, BITS/8, f.withPrefix);\
+            return toString_bin(_n, BITS/8, kprint_format_withPrefix(f));\
         case kprint_fmtHex:\
-            return toString_hex(_n, BITS/8, f.withPrefix, f.uppercase);\
+            return toString_hex(_n, BITS/8, kprint_format_withPrefix(f), kprint_format_uppercase(f));\
         default:\
-            printf("\n%u\n", f.dataFmt);\
+            printf("\n%u\n", kprint_format_dataFormat(f));\
             throw(ERR_FORMAT);\
             return NULL;\
     }\
@@ -138,18 +136,17 @@ __toString_uint_def(16)
 __toString_uint_def(32)
 __toString_uint_def(64)
 
-#define __toString_float_def(BITS) char* __toString_float##BITS(void* _n, int32 _f){\
-    kprint_format f=*(kprint_format*)&_f;\
-    switch(f.dataFmt | (uint32)0){\
-        case kprint_fmtFloat:\
+#define __toString_float_def(BITS) char* __toString_float##BITS(void* _n, uint32 f){\
+    switch(kprint_format_dataFormat(f)){\
+        case kprint_fmtFloat: ;\
             float##BITS n=*(float##BITS*)_n;\
-            return toString_float(n, f.withPrefix, f.uppercase);\
+            return toString_float(n, kprint_format_withPostfix(f), kprint_format_uppercase(f));\
         case kprint_fmtBin:\
-            return toString_bin(_n, BITS/8, f.withPrefix);\
+            return toString_bin(_n, BITS/8, kprint_format_withPrefix(f));\
         case kprint_fmtHex:\
-            return toString_hex(_n, BITS/8, f.withPrefix, f.uppercase);\
+            return toString_hex(_n, BITS/8, kprint_format_withPrefix(f), kprint_format_uppercase(f));\
         default:\
-            printf("\n%u\n", f.dataFmt);\
+            printf("\n%u\n", kprint_format_dataFormat(f));\
             throw(ERR_FORMAT);\
             return NULL;\
     }\
diff --git a/src/base/type_system/base_toString.h b/src/base/type_system/base_toString.h
index def1d4d..c3831cd 100644
--- a/src/base/type_system/base_toString.h
+++ b/src/base/type_system/base_toString.h
@@ -8,20 +8,20 @@ extern "C" {
 
 // functions for base types
 char* toString_int(int64 n);
-char* __toString_int8(void* n, int32 fmt);
-char* __toString_int16(void* n, int32 fmt);
-char* __toString_int32(void* n, int32 fmt);
-char* __toString_int64(void* n, int32 fmt);
+char* __toString_int8(void* n, uint32 fmt);
+char* __toString_int16(void* n, uint32 fmt);
+char* __toString_uint32(void* n, uint32 fmt);
+char* __toString_int64(void* n, uint32 fmt);
 
 char* toString_uint(uint64 n, bool withPostfix, bool uppercase);
-char* __toString_uint8(void* n, int32 fmt);
-char* __toString_uint16(void* n, int32 fmt);
-char* __toString_uint32(void* n, int32 fmt);
-char* __toString_uint64(void* n, int32 fmt);
+char* __toString_uint8(void* n, uint32 fmt);
+char* __toString_uint16(void* n, uint32 fmt);
+char* __toString_uuint32(void* n, uint32 fmt);
+char* __toString_uint64(void* n, uint32 fmt);
 
 char* toString_float(float64 n, bool withPostfix, bool uppercase); // very bad implimentation
-char* __toString_float32(void* n, int32 fmt);
-char* __toString_float64(void* n, int32 fmt);
+char* __toString_float32(void* n, uint32 fmt);
+char* __toString_float64(void* n, uint32 fmt);
 
 // universal functions
 char* toString_bin(char* bytes, uint32 size, bool withPrefix);
diff --git a/src/base/type_system/ktDescriptor.h b/src/base/type_system/ktDescriptor.h
index 9fb42d1..a12facb 100644
--- a/src/base/type_system/ktDescriptor.h
+++ b/src/base/type_system/ktDescriptor.h
@@ -12,7 +12,7 @@ typedef struct ktDescriptor{
     ktId id;
     uint16 size;
     void (*freeMembers)(void*); // NULL or function which frees all struct members
-    char* (*toString)(void* obj, int32 fmt); // NULL or function which generates string representaion of object
+    char* (*toString)(void* obj, uint32 fmt); // NULL or function which generates string representaion of object
 } ktDescriptor;
 
 #if __cplusplus
diff --git a/src/base/type_system/kt_functions.c b/src/base/type_system/kt_functions.c
index 1f85eea..a459d2a 100644
--- a/src/base/type_system/kt_functions.c
+++ b/src/base/type_system/kt_functions.c
@@ -58,7 +58,7 @@ void ktDescriptors_endInit(){
     printf("\e[92minitialized %u type descriptors\n", ktId_last);
 }
 
-void __kt_register(char* name, int16 size, void (*freeMembers)(void*), char* (*toString)(void*, int32)){
+void __kt_register(char* name, int16 size, void (*freeMembers)(void*), char* (*toString)(void*, uint32)){
     ktDescriptor typeDesc={
         .name=name,
         .size=size,
diff --git a/src/base/type_system/kt_functions.h b/src/base/type_system/kt_functions.h
index cdf5359..7274727 100644
--- a/src/base/type_system/kt_functions.h
+++ b/src/base/type_system/kt_functions.h
@@ -8,9 +8,8 @@ extern "C" {
 #include "ktId.h"
 #include "ktDescriptor.h"
 
-
 extern ktId ktId_last;
-void __kt_register(char* name, int16 size, void (*freeMembers)(void*), char* (*toString)(void*, int32));
+void __kt_register(char* name, int16 size, void (*freeMembers)(void*), char* (*toString)(void*, uint32));
 
 #define kt_register(TYPE, ID_VAR_NAME, FREE_MEMBERS_FUNC, TO_STRING_FUNC)\
     __kt_register(#ID_VAR_NAME, sizeof(TYPE), FREE_MEMBERS_FUNC, TO_STRING_FUNC);\
diff --git a/src/base/type_system/unitype.c b/src/base/type_system/unitype.c
index 7bf9f1b..59892fb 100644
--- a/src/base/type_system/unitype.c
+++ b/src/base/type_system/unitype.c
@@ -12,7 +12,7 @@ void Unitype_free(Unitype u){
 }
 void __UnitypePtr_free(void* u) { Unitype_free(*(Unitype*)u); }
 
-char* toString_Unitype(void* _u, int32 fmt){
+char* toString_Unitype(void* _u, uint32 fmt){
     Unitype* u=_u;
     ktDescriptor type=ktDescriptor_get(u->typeId);
     char* valuestr=type.toString(_u, fmt);
diff --git a/tests/main.cpp b/tests/main.cpp
index 39d2405..35967c1 100644
--- a/tests/main.cpp
+++ b/tests/main.cpp
@@ -9,6 +9,7 @@ void test_all(){
     test_hash_functions();
     test_hashtable();
     test_dtsod();
+    test_kprint_colors();
     printf("\e[96m--------------------------------------\e[0m\n");
 }
 
@@ -18,7 +19,8 @@ int main(){
     ktDescriptors_initKerepTypes();
     ktDescriptors_endInit();
     printf("\e[97mkerep tests are starting!\n");
-    optime("test_all",1,test_all());
+    // optime("test_all",1,test_all());
+    test_kprint_colors();
     printf("\e[0m\n");
     return 0;
 }
diff --git a/tests/test_autoarr-vs-vector.cpp b/tests/test_autoarr-vs-vector.cpp
index 1468463..37aba5e 100644
--- a/tests/test_autoarr-vs-vector.cpp
+++ b/tests/test_autoarr-vs-vector.cpp
@@ -4,7 +4,7 @@
 
 int64 _autoarrVsVector(uint16 blockCount, uint16 blockLength){
     uint32 count=blockLength*blockCount;
-    printf("\e[94mblock count: %u block length: %u count: %llu\n", blockCount, blockLength, (uint64)count);
+    printf("\e[94mblock count: %u block length: %u count: " IFWIN("%llu", "%lu") "\n", blockCount, blockLength, (uint64)count);
     Autoarr_int64* ar=Autoarr_create(int64, blockCount, blockLength);
     std::vector<int64> vec=std::vector<int64>();
     optime("Autoarr_add", 1, ({
@@ -15,7 +15,7 @@ int64 _autoarrVsVector(uint16 blockCount, uint16 blockLength){
         for(uint32 i=0; i< count; i++)
             vec.push_back(i);
     }));
-    int64 t;
+    int64 t=0;
     optime("Autoarr_get", 1, ({
         for(uint32 i=0; i< count; i++)
             t=Autoarr_get(ar, i);
diff --git a/tests/test_kprint_colors.c b/tests/test_kprint_colors.c
new file mode 100644
index 0000000..e23b8d9
--- /dev/null
+++ b/tests/test_kprint_colors.c
@@ -0,0 +1,47 @@
+#include "tests.h"
+#if defined(_WIN32)|| defined(_WIN64)
+    #include <windows.h>
+#endif
+
+#define testColor(COLOR) \
+    kprint_setColor(kprint_bgBlack | kprint_fg##COLOR);\
+    printf(#COLOR " ");\
+    kprint_setColor(kprint_bg##COLOR | kprint_fgGray);\
+    printf(#COLOR);\
+    kprint_setColor(kprint_bgBlack | kprint_fgBlack);\
+    printf("\n");
+
+void test_kprint_colors(){
+    IFWIN(
+        ({
+            HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
+            for(uint8 col=0; col<255; col++){
+                SetConsoleTextAttribute(hConsole, col);
+                printf("%u ",col);
+            }
+        }),
+        ({
+            for(uint8 col=0; col<255; col++)
+                printf("\e[%um%u ", col, col);
+        })
+    ); 
+    printf("\n");
+    
+    testColor(Black);
+    testColor(DarkRed);
+    testColor(DarkGreen);
+    testColor(DarkYellow);
+    testColor(DarkBlue);
+    testColor(DarkMagneta);
+    testColor(DarkCyan);
+    testColor(Gray);
+    testColor(DarkGray);
+    testColor(Red);
+    testColor(Green);
+    testColor(Yellow);
+    testColor(Blue);
+    testColor(Magneta);
+    testColor(Cyan);
+    testColor(White);
+    kprint_setColor(kprint_bgBlack | kprint_fgGray);
+}
\ No newline at end of file