To Get Bigger Tips, Waitresses Should Wear Red Male diners give bigger and more frequent tips to waitresses wearing red T-shirts than to those wearing black, white, blue, green, or yellow T-shirts, according to Celine Jacob and Nicolas Gueguen of the University of Southern Brittany. There’s no such effect from female customers, however, a finding that aligns with research suggesting that red increases women’s attractiveness to men. The study was conducted in France, where tips are generally included in the…