ANSI True Color (24-bit RGB) - 16 Million Colors in Terminal

24-bit True Color in Terminals

True color (also called 24-bit color or direct color) allows you to use any of the 16.7 million RGB colors in your terminal output. This is the most flexible ANSI color mode, matching the full color range of web and desktop applications.

Escape Sequence Format

• Foreground: \033[38;2;R;G;Bm where R, G, B are 0-255
• Background: \033[48;2;R;G;Bm where R, G, B are 0-255

Examples

# Custom orange foreground
echo -e "\033[38;2;255;165;0mOrange text\033[0m"

# Specific brand color (#6366F1 - Indigo)
echo -e "\033[38;2;99;102;241mBrand color\033[0m"

# Gradient effect
for i in $(seq 0 5 255); do
  echo -en "\033[38;2;${i};0;$((255-i))m#\033[0m"
done
echo

Converting Hex to ANSI True Color

To convert a hex color like #FF6B35:

hex_color = "FF6B35"
r = int(hex_color[0:2], 16)  # 255
g = int(hex_color[2:4], 16)  # 107
b = int(hex_color[4:6], 16)  # 53
print(f"\033[38;2;{r};{g};{b}mColored text\033[0m")

Terminal Support

True color is supported in:

• Full support: iTerm2, Windows Terminal, Alacritty, Kitty, WezTerm, GNOME Terminal (3.18+), Konsole (18.07+), foot
• Partial/No support: macOS Terminal.app (no support), older PuTTY versions, tmux (requires Tc or RGB terminfo capability)

Detecting True Color Support

# Check COLORTERM environment variable
if [ "$COLORTERM" = "truecolor" ] || [ "$COLORTERM" = "24bit" ]; then
  echo "True color supported"
fi

Fallback Strategy

For maximum compatibility, implement a fallback chain: true color > 256-color > 16-color > no color. Check the COLORTERM and TERM environment variables to determine the best color mode.