We have white cabinets & white appliances. The wall that connects the dining room and kitchen is light mocha. What color can we paint the other 3 walls that will warm up the kitchen. There are no windows.

I would suggest:
A warm brown, rich redish, not too dark chocolate with warm undertones for example:
Open the container of cocoa.
Use silver handles and accessories to add
brightness to the room.

Burnt orange and browns go well. A burnt orange with a clear crisp color would work well. Very hip color palette!

Look in your clothes closet. Which two colors are mostly there? You will probably like some version of those colors. I once hung curtains [with a flourescent light behind them to simulate a window] over a blank wall. My kitchen there didn't have windows, either.

the kitchen i have the base color is brown and the upper portion is brick/burnt orange with white chair rails and molding the idea is to color the cabinets brown and accent with silver what other colors would brighten to make the kitchen seem not so dark?

I agree with the other suggestions that burnt orange is the way to go if you want to coordinate with the colors you already have and warm up the room. Can you post some pictures?