Looking back on earlier versions where the colors are much darker than they are now and thinking about
past lighting conditions I've done (as a side note: I will never dither like that again), I can see where my mistakes and habits have come from in terms of lighting. I also need to fix a palette that I pull a lot of colors from.
Either way, I think the point is ultimately that a lot of background elements are too strong, and need to be nerfed.

I pushed the two big lights more towards the back, and with the new implied distance I was able to have another light where the close spotlight used to be, to help have something to fill negative space and frame the image.
I'm trying to imply that the grid is sort of glowing without it being distracting. Unfortunately the shading here might be banding, and I'm not sure what to do about that (I also might not have cleaned up a lot of dirty artifacts that may exist by the grid lines.)
Started adding more colors. Unfortunately this leads to a lot of colors currently underused as a result, and a lot of straight ramps (but I can adjust the hues later on once a lot of the colors find their uses and I start intermixing ramps).
I also have to apologize, but despite it being better to have warm colors up front, I just love the kind of atmosphere the warmer colors of the holographic backdrop behind the monster has. Making the castle very light was an accidental decision.
Again, very incomplete and a lot of messy clusters here and there still.
I also want to note: I'll be adding outlines last or close to last, as a sort of cherry on top of a finished cake once I get everything else working.