I'm making some graphics wherein I want to loop through the RedGreenBlue color-components. Sometimes I can simply write something like: 

$x = 20;
$white=$img->colorAllocate(255,$x*2,255);
$img->line(0,0,50,50,$white);
$white = $img->colorAllocate(255,$x*10,150);
$img->line(50,50,150,250,$white);

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And then it works. Sometimes this doesn't work so i try to deallocate f.e.:

$blue = $img->colorAllocate(0,0,25);
$img->colorDeallocate($blue);
$blue = $img->colorAllocate(0,0,25*$teller);

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But this doesn't work either. Can someone tell me how to do this? Thank you.

In reply to allocating/deallocating colors with GD module. by Anonymous Monk

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