Must you use bright sunshine yellow for the door? Can you not use a more browned-down yellow or a more subdued buttery yellow, a beautiful woven basket with yellow daisies or sunflowers with lots of greenery and some soft pink little vinca, and some brown ribbon with yellow polka dots, and perhaps use antique brass hardware.

How about the oil rubbed bronze (orb) finish? When I was looking a couple years ago there were lots available in that finish. Seems like it would be dark enough to contrast with the yellow like black would. A yellow door sounds very pretty :-)

What color yellow are you thinking about? Not a kiddy yellow, right?

ORB would be my pick.