Rainbow Boa off feed

Im fairly nervous i fed my boa last week, only issue is he threw up about three days later, and this week he wont eat. should i be alarmed? i also noticed yesterday his colors were pretty grey so i thought he was going to shed and today his colors are brighter and not grey at all, but theres no shed in the cage i looked every where for it. just wondering what all this means and if i should be worried.

Give it a few more days. If he was grey then got brighter he'll probably shed soon. Make sure your husbandry is right and nothing is around to stress him out.

I'd offer him food on the next scheduled feeding day. If he eats, I'd think it a fluke thing and he should be fine. If he doesn't, I'd personally think about a vet visit.

This is what I would in general for any snake. I do not have BRB so do not know specifics of what could be wrong.