Convert Hex Colors to ANSI Escape Codes

Converting Hex Colors to ANSI

Web developers frequently need to replicate hex colors in terminal output. This guide covers converting hex colors to both true color (24-bit) and 256-color ANSI escape sequences.

Hex to True Color

The conversion is straightforward — parse the hex into RGB components:

def hex_to_ansi_truecolor(hex_color, is_bg=False):
    hex_color = hex_color.lstrip('#')
    r = int(hex_color[0:2], 16)
    g = int(hex_color[2:4], 16)
    b = int(hex_color[4:6], 16)
    prefix = 48 if is_bg else 38
    return f"\033[{prefix};2;{r};{g};{b}m"

Hex to Nearest 256-Color

For terminals that do not support true color:

def hex_to_ansi256(hex_color):
    hex_color = hex_color.lstrip('#')
    r = int(hex_color[0:2], 16)
    g = int(hex_color[2:4], 16)
    b = int(hex_color[4:6], 16)

    # Check grayscale
    if r == g == b:
        if r < 4: return 16
        if r > 248: return 231
        return round((r - 8) / 10) + 232

    # Map to 6x6x6 cube
    values = [0, 95, 135, 175, 215, 255]
    ri = min(range(6), key=lambda i: abs(values[i] - r))
    gi = min(range(6), key=lambda i: abs(values[i] - g))
    bi = min(range(6), key=lambda i: abs(values[i] - b))
    return 16 + (36 * ri) + (6 * gi) + bi

Popular Hex Colors and Their ANSI Equivalents

Hex	Name	True Color Code	Nearest 256
#FF5733	Burnt Orange	38;2;255;87;51	202
#3498DB	Dodger Blue	38;2;52;152;219	68
#2ECC71	Emerald	38;2;46;204;113	42
#E74C3C	Alizarin	38;2;231;76;60	196
#9B59B6	Amethyst	38;2;155;89;182	133
#1ABC9C	Turquoise	38;2;26;188;156	36

Node.js Implementation

function hexToAnsi(hex, isBg = false) {
  const r = parseInt(hex.slice(1, 3), 16);
  const g = parseInt(hex.slice(3, 5), 16);
  const b = parseInt(hex.slice(5, 7), 16);
  const prefix = isBg ? 48 : 38;
  return `\x1b[${prefix};2;${r};${g};${b}m`;
}

// Usage
const red = hexToAnsi('#FF5733');
console.log(`${red}Hello World\x1b[0m`);

This makes it easy to use your application's brand colors consistently in both web and terminal contexts.