Sort colors from dark to light

sort-colors.php

<?php

function cf_sort_hex_colors($colors) {
	$map = array(
		'0' => 0,
		'1' => 1,
		'2' => 2,
		'3' => 3,
		'4' => 4,
		'5' => 5,
		'6' => 6,
		'7' => 7,
		'8' => 8,
		'9' => 9,
		'a' => 10,
		'b' => 11,
		'c' => 12,
		'd' => 13,
		'e' => 14,
		'f' => 15,
	);
	$c = 0;
	$sorted = array();
	foreach ($colors as $color) {
		$color = strtolower(str_replace('#', '', $color));
		if (strlen($color) == 6) {
			$condensed = '';
			$i = 0;
			foreach (preg_split('//', $color, -1, PREG_SPLIT_NO_EMPTY) as $char) {
				if ($i % 2 == 0) {
					$condensed .= $char;
				}
				$i++;
			}
			$color_str = $condensed;
		}
		$value = 0;
		foreach (preg_split('//', $color_str, -1, PREG_SPLIT_NO_EMPTY) as $char) {
			$value += intval($map[$char]);
		}
		$value = str_pad($value, 5, '0', STR_PAD_LEFT);
		$sorted['_'.$value.$c] = '#'.$color;
		$c++;
	}
	ksort($sorted);
	return $sorted;
}

Unfortunatly not really working for me.
I have written by my own ;)

function cf_sort_hex_colors($colors) {
        $sorted = [];
        foreach ($colors as $color) {
            if (strlen($color) == 6) {
                $key = "";
                for($i=0;$i<6;$i++)
                {
                    $key .= sprintf('%02d',$this->map[substr($color, $i, 1)]);
                }
                $sorted[$key] = $color;
            }
        }

        ksort($sorted);
        return array_values($sorted);
    }

The color array is that way : ['eeeeee','ffffff', ...]. If the color code are using # juste add (as seen in the upper example :
$color = strtolower(str_replace('#', '', $color)); at the line 10 of the function replace $sorted[$key] = $color; by $sorted[$key] = '#'.$color;