we use a aaf round trip workflow for color. howeverm when exported from resolve and back to avid. the color looks drastically different. what seting should i pay attention to. thanks 

One thing to make sure of is that on the return from Resolve, no color corrections are left on the sequence.

If the sequence you sent to Resolve had CCs on some or all of the clips, and you used the Resolve Avid Rountrip workflow, those CCs will be left in place on the way back.  This really freaked me out the first time I did a round trip!!

My work flow now is when locked, I dupe the sequence to a new bin.  I then delete all audio tracks, collapse any muticams, get rid of all color corrections, remove color adapters (LUTs) and get rid of all renders.  This gives me a "clean" sequence from which I make an AAF to go to Resolve.

Give that a try.

Jef