color_difference() public static méthode

A value higher than 500 is recommended for good readability.
public static color_difference ( string $color_1 = '#ffffff', string $color_2 = '#000000' ) : string
$color_1 string The 1st color.
$color_2 string The 2nd color.
Résultat string
 public function test_color_difference()
 {
     $this->assertEquals('0', Kirki_Color::color_difference('fff', '#ffffff'));
     $this->assertEquals('765', Kirki_Color::color_difference('fff', '000'));
     $this->assertEquals('765', Kirki_Color::color_difference('#000000', '#ffffff'));
     $this->assertEquals('522', Kirki_Color::color_difference('#f2f2f2', '#c00'));
     $this->assertEquals('39', Kirki_Color::color_difference('#f2f2f2', '#ffffff'));
 }