$r
$r : float
Red
Image RGB color class
setR(mixed  $r) : \Pop\Image\Color\Rgb
                Set the red value
| mixed | $r | 
setG(mixed  $g) : \Pop\Image\Color\Rgb
                Set the green value
| mixed | $g | 
setB(mixed  $b) : \Pop\Image\Color\Rgb
                Set the blue value
| mixed | $b | 
toCmyk() : \Pop\Image\Color\Cmyk
Convert to CMYK
toGray() : \Pop\Image\Color\Gray
Convert to Gray