crome pipes turn a brown/gold/blue as they get old and hot or if you overheated it etc.
only reason i can think of for flames is a bunch of fuel built up in the pipe,if so it should go away after running a while, otherwhise idk
if your pipes look diferent then theres a chance your jetting is off frome one side to another , keep an eye on it, things run best right before they blow up. :ermm: