Image color modification via Javascript or PHP

I need to change the color of a transparent PNG that will not touch the 100% transparent part via Javascript or PHP. I would like to the the exactly same thing that Photoshop color overlay does on a layer (100% color overlay - no hue change).

I have already found a filter that can flip the image horizontally on S开发者_运维技巧tackOverflow (thanks guys!) but the solution to this I cannot find anywhere.

Please help and thanks in advance!

Try imagefilter with IMG_FILTER_COLORIZE