diff --git a/include/tim.h b/include/tim.h
index 86a493f..ff1f9ce 100644
--- a/include/tim.h
+++ b/include/tim.h
@@ -66,7 +66,10 @@ extern "C" {
 #pragma region types
 
 
-/* first 16 colors from xterm256 supported by any terminal emulator */
+// 16 ANSI colors supported by any terminal emulator.
+// It's better to use xterm256 colors istead,
+// because ANSI colors look different in each terminal.
+// https://www.ditig.com/256-colors-cheat-sheet
 enum {
     TimColor16_Black       = 0x00,
     TimColor16_DarkRed     = 0x01,
diff --git a/readme.md b/readme.md
index 1457d0b..559bf95 100644
--- a/readme.md
+++ b/readme.md
@@ -65,8 +65,9 @@ The layout automatically adopts to terminal window resize events.
 
 ## colors
 Colors are stored as 8-bit values.
-Most terminals support 16 basic colors. You can see them in TimColor16 enum.
-There is also support for xterm-256 colors.
+Most terminals support 16 ANSI colors. You can see them in TimColor16 enum.
+It's better to use xterm256 colors istead, because ANSI colors look different in each terminal.
+https://www.ditig.com/256-colors-cheat-sheet
 ![xterm-256 color chart](./256colors.jpg)
 
 ## events