public function getByIndex($index)
    {
        if ($index === 0) return $this->darkGray;
        if ($index === 1) return $this->midColor;
        if ($index === 2) return $this->lightGray;
        if ($index === 3) return $this->lightColor;
        if ($index === 4) return $this->darkColor;
        return null;
    }