According to an article from the WSJ, USB apparently thinks it can. And does!
Their 43-page (yeah, you read that right!) guidelines for staff aim to assure employees dress to impress clients.
"As if taking a cue from style manuals, which often stress the importance of well-cut basic outfits in neutral colors, the bank expects its retail banking staff to wear suits in dark grey, black or navy blue, since these colors 'symbolize competence, formalism and sobriety.'"
You can have a look at the dress code for yourself, here.