Question : PHP GD add colour overlay to image

Hi experts,

I have a PNG which is partially transparent and partially filled black (see attachment arrow.png).

arrow.png (332 bytes) (File Type Details) 

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I need to know how I can use PHP and GD to overlay the black portion with an arbitrary colour at 75% opacity (see attachment arrow-colored.png for expected result).

arrow-colored.png (339 bytes) (File Type Details) 

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Even better if this can be done with Drupal imageapi? The biggest catch is the overlay colour has to be a variable.  

Answer : PHP GD add colour overlay to image

Your most likely looking at a very special piece of equipment that would be like a router that breaks the t1's to coax. Your big problem is going to be the TV side. At this point for you and your clients sanity i would be looking at a cost factor and also exploring different options.