Good idea, but switch tops won't even been seen unless you get transparent caps, which I don't think most people like.
I think something more useful is for you to get mx stems made for cheap. It's ridiculous to pay 80cents for a whole mx clear switch to only harvest the stems. So maybe make duplicates of stems in mx reds, clears, and browns. I'm guessing blue/green will be much more expensive because it's a 2-piece design.
think about all the color is the same under your keycaps, that is really cool, and i believe many people will like it.
and two main reaseons i don't want to make any stems are: 1. quality. These stuff will be produced by a great chinese plastic factory. it is OK to make the top but not the stem. A stem is a moving part under high pressure, There have been a lot of clone switches such as Kailh above, but it is really easy to break, we don't have that kind of German industrial ability. instead, a top cover is so simple, we don't push it, or use it. it is only for good looking and keep dust away.
2. keep the stem market simple, i don't want to clone any of the stems since they are made by Cherry, not by someone else and not replaceable, switches stem is the most important part of a mechanical keyboard. i somehow " respect" the stems. if i made exactly the same stem, like the reworked cherry red ESC, everything will be massed up