This is something I’ve thought a bit about. I don’t really want to add color or color changes, since those are fairly eye-catching. If the entire upper field suddenly turned dark, that’d really stand out. Personally, I’ve managed to largely get used to the lack of color association… with a healthy helping of WaniKani Override, I suppose. 
I’m not sure, though - is this a big problem? I’d love to hear all your thoughts on whether a tiny bit of color difference is needed. If it’s something that really hurts the usefulness of the user style, I should probably take a look at changing it up. What do you all think?