BEIGE or CLEAR is the best under whites. Period. Here are photos to make this easy:
As far as sheers go, I am a big fan of clear straps, if the straps show through the sheer. Otherwise, beige is still best. I know beige is probably the least sexy color, but the idea is to showcase your shirt or your shoulders or your figure and NOT your bra.
So please, I’M BEGGING YOU, put on beige under your summer whites, and forward this to your friend who hasn’t got the memo yet. The photos don’t lie.