In a twist, I propose a variation: An option box [X] enforce same colour for just panels (to mimic aestethics)
And we need it only if the user selects <ignore> or <similar> in the sliding selector.
The effect is similar to the OP questions, but not cumbersome as to mark each and all parts we want in that precise colour.
An engine should be simple.
In that way, the engine has to check the equality only inside 1 list (panels) and fly on the rest...
Performance-wise, it can't be slower: because it does a <exact> match on panels, than a <ignore> search on the rest, which the engine is already capable of doing. It should sit between the 2 kind of builds.
If tested, and working good as I expect, it stays open to enhancements.
[X] enforce same colour for just panels (to mimic aesthetic)
[X] enforce same colour for just beams (to mimic aesthetic)
[X] enforce same colour for just another category worth for...