0 ) { $s = 100 * ( $chroma / $max_rgb ); if ( $r === $min_rgb ) { $h = 3 - ( ( $g - $b ) / $chroma ); } elseif ( $b === $min_rgb ) { $h = 1 - ( ( $r - $g ) / $chroma ); } else { // $g === $min_rgb $h = 5 - ( ( $b - $r ) / $chroma ); } $h = 60 * $h; return array( $h, $s, $v, $l ); } else { return array( 0, 0, $v, $l ); } } } if ( ! function_exists( 'change_color_luminescence' ) ) { function change_color_luminescence( $hex, $amount ) { $hex_without_hash = substr( $hex, 1, strlen( $hex ) ); $rgb = hex_to_rgb( $hex_without_hash ); $hsvl = rgb_to_hsvl( $rgb ); return 'hsl( ' . $hsvl[0] . ',' . $hsvl[1] . '%,' . ( $hsvl[2] + $amount ) . '%)'; } }