sean: many buttons in ardour have THREE states, not two:
off
explicitly enabled/on
implicitly enabled/on
An example of the last: you solo some track, which mutes others. The mute buttons of the other tracks change color, but to the “implicit” color/state, so that you can see at a glance what is happening. It would be (and used to be) confusing when you cannot see what is happening, which is what occurs when buttons have only two states.
At all, if you go to “Preferences>Theme>Colors>Items” you can find “solo button>fill active” and “mute button>fill active”. Just choose any color for these items.
wait a minute… solo/mute buttons have consistend and sensible colours for me. Any chance you are in “Harlequin mode”? I learned about this from x42’s post on this thread: https://community.ardour.org/node/14057.