Is having brown hair+brown eyes an example of this trope in play?
I can see it being so if there are no limit to what kind of color hair and eyes could have in the universe the example is set in, then brown is as unusual as any other color.
The idea of this trope is that the eye and hair color match, whether it's uncommon or not. Usually, at least one of the two is uncommon: Blue is common for eyes, but not so much for hair. To be fair, there can be some more "mundane" or "realistic" versions of this trope (like Scaresteam, LordLaharlsVassal, and the other dude, but also me (to an extent), where my hair can sometimes have a dark brassy tone* to match my eye color); either way, it creates a kind of effect of matching. But maybe it is up for debate. Still, Tropes Are Not Bad.
Edited by Stoogebie
The Higurashi one..In what adaptation does Keiichi have brown eyes? An obscure manga?
How about bald people? Y'know, 'cause most windows don't have any color?