[ Grell perks, positively beaming! Hooking an arm into the crook if his elbow, she pulls him over to the waistcoat selection. ]

When in doubt, stick with neutrals. Greyscale, shades of brown, cremes, and whites... [ To demonstrate, she pulls out a check patterned vest with cool grey tones, and another mid-brown vest donning a wide window pane pattern in green. ] And see how this second incorporates the color of the jacket?

[ Piling those into his arms, she shuffles for one more, pulling a warm plum vest. ] Colors that compliment green are red and purples, and since we don't want you suited to court Saint Nicolas, I think something like this would be better.