Dials With Nonnumeric Settings

I’ve been struggling with this problem for a couple of days now. I’m trying to create a dial that can be set in several ways but none of the settings are labeled with numbers. As an example, let’s say I have a dial that goes from “RED” to “GREEN” to “BLUE”. Is the set it to rule something I can use here? It needs a thing or a value as far as I can tell. I thought about enumerating each setting with a number, but there doesn’t seem to be a rule for that. I also considered making each setting its own device but ran into complications there as well. Any advice?

Instead of setting the dial to "red":

Setting it to takes a topic (i.e. some text) as its second argument.

This thread might also be helpful:

https://intfiction.org/t/a-machine-with-different-settings/7616/1