Bra straps are an office no-no, but what about on causal summer occasions? I'd rather show my bra straps with a tank top than go without or suffer with a padded (i.e. warm) strapless. Although, I can't show beige or white straps. Those colors are just too underwear. When I do let my straps show, I try to make sure they're some sort of color that looks like it goes with the outfit. Particular? Yes, but those are my personal rules.