Today I'm wearing a teal sweater, similar to this but the sweater is darker:
with a light blue cami, and trousers from J Crew that they called "mushroom heather" - kind of a light pinky/browny tweed.
It all works except the shoes. Before I tell you which ones I'm wearing, what color would you be wearing? (None of these are actually the shoes, just the colors. The real shoes are plain pointed toe or round toe pumps.)
Brown! Camel is too lite for those pants I think (as I am imagining them) and they are probably off the color pallette of the pants. Black might look ok, but brown if you are really looking to coordinate
I think I know the color you're describing and I can understand your confusion because from what I remember the "mushroom" color is brown with gray undertones. I can see how you would be considering black or brown shoes but I think I would definately go with the dark brown, especially because I love teal with brown so I would want to bring out the warm tones in the pants.