public function grayscale()
    {
        $gray = min(
                255
                , round(
                        0.299 * $this->getRed() +
                        0.587 * $this->getGreen() +
                        0.114 * $this->getBlue()
                )
        );

        return $this->setFromArray(array(
                    $gray, $gray, $gray, $this->getAlpha()
        ));
    }
public function grayscale()
    {
        $gray = min(
                255
                , round(
                        0.299 * $this->getRed() +
                        0.587 * $this->getGreen() +
                        0.114 * $this->getBlue()
                )
        );

        return $this->setFromArray(array(
                    $gray, $gray, $gray, $this->getAlpha()
        ));
    }
public function grayscale ( ) { $ gray = min ( 255 , round ( 0.299 * $ this -> getRed ( ) + 0.587 * $ this -> getGreen ( ) + 0.114 * $ this -> getBlue ( ) ) ) ; return $ this -> setFromArray ( array ( $ gray , $ gray , $ gray , $ this -> getAlpha ( ) ) ) ; }
Gray current color

@return \Jaguar\Color\RGBColor
Gray current color