Pastel shades can clash with the rich undertones in warm blonde hair, making your skin look dull and prompting people to ask if you caught that cold that’s going around. Hudson needed a lot of bronzer to overcome that problem with this dress.

“Cooler colors — like mint or olive green — when worn by someone with warm blonde hair can grey the skin and make highlights look yellow and brassy,” Kirsh says. The same goes for hues such as pale shades of blue, pink, and yellow, as well as reds that have a blue undertone. So unless you’re going for that undead vampire look, skip the pales.