What is the color format to use with imagerotate() in PHP?

Question

In PHP; what format is used for the background color option in the function imagerotate().

$color = "???????";
imagerotate($image, $degrees, $color);

I have tried:

$color = "#FFFFFF";
$color = "255255255";

Answer 1

I think you have to specify it with imagecolorallocate():

// 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);

via the man pages

Answer 2

You need to previouslly allocate the desired $color with imagecolorallocate() or imagecolorallocatealpha().