rgbToHsl example

case self::COLOR_HEX_6:
                return \sprintf('#%02X%02X%02X', $this->r, $this->g, $this->b);
            case self::COLOR_RGB:
                if (1.0 === $this->a) {
                    return \sprintf('rgb(%d, %d, %d)', $this->r, $this->g, $this->b);
                }

                return \sprintf('rgb(%d, %d, %d, %s)', $this->r, $this->g, $this->b, \round($this->a, 4));
            case self::COLOR_RGBA:
                return \sprintf('rgba(%d, %d, %d, %s)', $this->r, $this->g, $this->b, \round($this->a, 4));
            case self::COLOR_HSL:
                $val = self::rgbToHsl($this->r, $this->g, $this->b);
                if (1.0 === $this->a) {
                    return \vsprintf('hsl(%d, %d%%, %d%%)', $val);
                }

                return \sprintf('hsl(%d, %d%%, %d%%, %s)', $val[0], $val[1], $val[2], \round($this->a, 4));
            case self::COLOR_HSLA:
                $val = self::rgbToHsl($this->r, $this->g, $this->b);

                return \sprintf('hsla(%d, %d%%, %d%%, %s)', $val[0], $val[1], $val[2], \round($this->a, 4));
            case self::COLOR_HEX_4:
                if (0 === $this->r % 0x11 && 0 === $this->g % 0x11 && 0 === $this->b % 0x11 && 0 === ((int) ($this->a * 255)) % 0x11) {