Well I guess you could call them a sparkle gray actually, now that I look close they look like a metallic gray paint you might see on a custom car. Not really like actual metal.
What are mushroom cups vs straight cups. They are just like the cups on my 225i but silver metal (or whatever it is) instead of black plastic.
If you have the 225i model, you have the beveled/mushroomed edges on the far outside of the ear cup, where as the 225 (non-i's) cups are flat.
SR225-Flat cup
SR225i-Beveled/Mushroom cup