Returns a color identifier representing the color composed of the given RGB components.
imagecolorallocate() must be called to create each color that is to be used in the image represented by image.
An image resource, returned by one of the image creation functions, such as imagecreatetruecolor().
Value of red component
Value of green component
Value of blue component
These parameters are integers between 0 and 255 or hexadecimals between 0x00 and 0xFF.
$im = imagecreate(100, 100);
// sets background to red
$background = imagecolorallocate($im, 255, 0, 0);
// sets some colors
$white = imagecolorallocate($im, 255, 255, 255);
$black = imagecolorallocate($im, 0, 0, 0);
// hexadecimal way
$white = imagecolorallocate($im, 0xFF, 0xFF, 0xFF);
$black = imagecolorallocate($im, 0x00, 0x00, 0x00);