Random gradient color by weight

gradient_random.php

/**
 * @param mixed $color1 The first hex/rgb array gradient color
 * @param mixed $color2 The second hex/rgb array gradient color
 * @param mixed $weight Weight of color 1 against color 2. Should be a float between 0 and 1
 * @return string A hex color mix of the two gradient colors based on weight
 */
function pick_hex($color1, $color2, $weight) {
    $w1 = $weight;
    $w2 = 1 - $w1;
    if (is_string($color1)) {
        list($r1, $g1, $b1) = sscanf($color1, "#%02x%02x%02x");
    } elseif (is_array($color1)) {
        $r1 = $color1[0]; $g1 = $color1[1]; $b1 = $color1[2];
    }
    if (is_string($color2)) {
        list($r2, $g2, $b2) = sscanf($color2, "#%02x%02x%02x");
    } elseif (is_array($color2)) {
        $r2 = $color2[0]; $g2 = $color2[1]; $b2 = $color2[2];
    }
    $rgb = [round($r1 * $w1 + $r2 * $w2),
        round($g1 * $w1 + $g2 * $w2),
        round($b1 * $w1 + $b2 * $w2)];
    return sprintf("#%02x%02x%02x", $rgb[0], $rgb[1], $rgb[2]);
}