Jim, since my comment on another thread may have 'stirred' this interest on your part
I will respond with this. It think all too often we look at woods in their present state, and they appear to coordinate very well. However, most all woods change dramatically in color over time. It takes some knowledge and experience with that in order to predict what the combination will look like 2, 3 or 5 years down the road. The walnut/cherry is just one instance of that. Another might be Osage Orange paired up with walnut - today, they might look OK together (not my pick, but not bad.) 3 years from now, the OO will have mellowed into a brown, while the walnut is getting an amber hue.
All that said, walnut/maple were created to be together!!!
Particularly, curly maple and walnut!
Also, BLM burl/walnut do very well together.
And, to add to your Mom's advice, black goes with nearly anything as well.