So I noticed that if you actually make the layer color something
greater than one, which people have been hesitant about doing, you get some crazy results, and can get all kinds of permutations of color that look really cool. I might post some pictures later. But that's not what this thread is about. This thread is about what oversaturating Layer 4 does to the player character, which is this:

Now in some ways this is a problem, and I actually tweeted Edmund asking if there was any way he could add two more center layers that you can put solid tiles on, which would be helpful for a lot of reasons. The fact is sometimes maybe you want your background to look crazy without rubbing off on the player.
On the other hand, this opens up a whole range of possibilities for what we can make the characters look like. It would be very easy to make Viridian look like every member of his crew, since they're all just different colored versions of him. People like Josef, who have more complex color gradients, can be made to look like above. And beyond. The possibilities are pretty endless. Do your own experiments, take some screenshots, and post the pictures here.