PHP Functions to Convert Hex to RGB & HSL

colors.php

<?php

function rgb($hex)
{
    [$r, $g, $b] = sscanf($hex, "#%02x%02x%02x");

    return [$r, $g, $b];
}

function hsl($hex)
{
    $rgb = array_map(function ($dec) { return $dec / 255; }, rgb($hex));

    $c_min      = min($rgb);
    $c_max      = max($rgb);
    $c_delta    = $c_max - $c_min;

    if ($c_delta === 0)             $hue = 0;
    else if ($c_max === $rgb[0])    $hue = ( ($rgb[1] - $rgb[2]) / $c_delta ) % 6;
    else if ($c_max === $rgb[1])    $hue = ( ($rgb[2] - $rgb[0]) / $c_delta ) + 2;
    else if ($c_max === $rgb[2])    $hue = ( ($rgb[0] - $rgb[1]) / $c_delta ) + 4;

    if ( ($hue = round($hue * 60)) < 0 ) {
        $hue += 360;
    }

    $lightness = ( ($c_max + $c_min) / 2 ) * 100;
    $saturation = $c_delta === 0 ? 0 : (
        ($c_delta / (1 - abs(2 * $lightness - 1)) * 100)
    );

    if ($saturation < 0) {
        $saturation += 100;
    }

    $lightness  = round($lightness);
    $saturation = round($saturation);

    return [
        $hue, $saturation, $lightness
    ];
}