Is it just me or is it common for teeth to really look yellow soon after getting braces - despite ongoing good oral hygiene....??? I'm only one week in Clarity SL ceramics and already my teeth (which aren't naturally really white) appear very yellow...

Of course I've always loved drinking coffee but before braces, rinsing and brushing afterwards kept the bad staining away.... now, not so much..... Could the "etching" process at braces application have made my teeth even more prone to yellowing...????
Please don't tell me to quit coffee.... I'm still in the early sensitive teeth/ripped up inside of mouth due to hooks stage, so whilst I can't enjoy eating anything much that isn't sloppy or slippery, I do still get to savor a great big cup or two of my favorite brew....
My Orthodontist's office did tell me that I could do whitening whilst in braces. Has anyone done that?
If so, what did it involve/cost and what were the results like..?
Thanks for any advice!!!