color-utilities-in-javascript

name: color-utilities-in-javascript description: Explore helpful color utility functions, like RGB to HSL, HEX to RGB, and HSL to HEX, generated with the assistance of GitHub Copilot. metadata: url: https://rodydavis.com/posts/snippets/typescript-color-utilities last_modified: Tue, 03 Feb 2026 20:04:31 GMT

Color Utilities in JavaScript

Color utilities generated by GitHub Copilot.

Convert an RGB color to HSL

function rgbToHsl(r, g, b) {
    r /= 255;
    g /= 255;
    b /= 255;
    var max = Math.max(r, g, b);
    var min = Math.min(r, g, b);
    var h, s, l = (max + min) / 2;
    if (max == min) {
        h = s = 0;
    } else {
        var d = max - min;
        s = l > 0.5 ? d / (2 - max - min) : d / (max + min);
        switch (max) {
            case r:
                h = (g - b) / d + (g < b ? 6 : 0);
                break;
            case g:
                h = (b - r) / d + 2;
                break;
            case b:
                h = (r - g) / d + 4;
                break;
        }
        h /= 6;
    }
    return [h, s, l];
} 

Convert HEX to RGB

function hexToRgb(hex) {
    var result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
    return result ? {
        r: parseInt(result[1], 16),
        g: parseInt(result[2], 16),
        b: parseInt(result[3], 16)
    } : null;
}

Convert HSL to HEX

function hslToHex(h, s, l) {
    var r, g, b;
    if (s == 0) {
        r = g = b = l;
    } else {
        var hue2rgb = function hue2rgb(p, q, t) {
            if (t < 0) t += 1;
            if (t > 1) t -= 1;
            if (t < 1 / 6) return p + (q - p) * 6 * t;
            if (t < 1 / 2) return q;
            if (t < 2 / 3) return p + (q - p) * (2 / 3 - t) * 6;
            return p;
        };
        var q = l < 0.5 ? l * (1 + s) : l + s - l * s;
        var p = 2 * l - q;
        r = hue2rgb(p, q, h + 1 / 3);
        g = hue2rgb(p, q, h);
        b = hue2rgb(p, q, h - 1 / 3);
    }
    return "#" + (1 << 24 | r << 16 | g << 8 | b).toString(16).slice(1);
}