Tif, I'm not talking to you since you made me buy five pairs of Allen Edmonds in a week.
OK, brown calf. Suede, actually.
A brown suede one, made out of a piece of a cow. And your wife is wrong about the black dial/brown strap (with all due respect): it will warm the whole thing up nicely. Especially with the suede. Check out for example every Panerai ever.
A black and white spectator ("Broadstreet), a black patent with blue contrast stitching ("Times Square"), a brown shortwing - forgotten the name, a black "Strawfut" and a burgundy shell NST ("Bradley")
I've never once worried about matching watch strap to shoes, and I'm OCD. This really shouldn't factor in to the decision IMO. I could be swayed in either direction as long as the brown is a darker shade. There are more Speedy's on black straps that I like, but my favorites have been on brown straps; guess that speaks to the ease/difficulty of getting the right match between the two options.