Reconsider Overall Aesthetics Policy
There are a few examples that managements policy for the overall appearance of the game is to make the UI drab to emphasize the creations.
Changing the skybox back to the grey nebula,
Insisting on the bright/high contrast 'SE theme colours' for the Main Menu background video competition,
The UI itself, and
Declining coloration of inventory icons idea.
There's probably more examples, but my point is that while I can understand wanting to emphasize the cool stuff you can make with SE, having everything else be so drab really makes the 100's of hours it can take to make something, less enjoyable than it could be.
tl;dr The game stands on its own without needing visual trickery to dazzle.