The colouring is normal - you get that with albinos and leucistics, it's just their internal organs showing through their skin.
Lumpiness and floaty bum syndrome can often be attributed to digestive issues - possibly gravel in his tummy or gas - and it will pass on it's own. He may suddenly try doing an inpression of an eel - darting about, bumping in to things - it probably means he is uncomfortable and it's the same as you squirming when you have gassy cramps!