The following GD issue is all-too common: https://stackoverflow.com/questions/5773032/how-to-stop-gd2-from-washing-away-the-colors-upon-resizing-images
Basically anyone who's ever accepted uploaded images and resized or converted them, has bumped into this. Only Imagick makes it possible to work around this issue, it's not possible with GD, at all - and the internal behavior of GD is arguably "wrong", as the visible output of simply opening and saving a JPEG image with GD is mangled with washed-out colors. I am starting to wonder why GD is the default in PHP? It's a pretty outdated library with a clunky API - we have Imagick with a much more concise API and a ton more useful features. Why is the less-capable image library the default on the PHP platform? Why not Imagick?