No, you don't get to change their colours, these are just the upgrade levels. It is a change I didn't show in the previous devlog, so here it is - turbines and refineries are upgrade-able with a new level.

Another experimental change I added (that hopefully is good), is that refineries can also be optionally assigned with a worker to prioritize that refinery's production. Useful if you have a refinery producing circuits but the rest are minerals, and you want the circuits to be worked on.