Do switches and outlets have to match?

So we have a new place and it has the old style rocker switches. I'm replacing them with Decora style. Question is this: the kitchen cabinets, counter and backsplash almost demand a brown colored outlet/switch and plate. That is how the old owners had it and we agree...but now what about the rest of the house? How do you all do it? Same colors throughout the house? Depends on room color? One color for switches and another for outlets? My mindset in doing high end homes was always same color everywhere for consistency.....

The old owners had it different depending on the room and color, but I'm having trouble wrapping my head around that. So what d'ya think?

And trust me, I know, first world problem........