I find after I look away from the editor, after using it for a while, I will have a blue bar shape burned into my retina.

I've used the config.txt gui settings but they seem to only change the body of the editor and not the bars at the top and the bottom.

Install latest version of Pico-8, has eye-soothing blue background, not gray.

If this is not what you're after, you can do this either in code or immediate mode:

pal(8,12,1)
poke(24366,1)

Also changes the cursor from RED to BLUE. :)

It's temporary though, once you run your code, the colors are reset. Include these two-lines at the end of your code though and they will be active any time you run.

For more information on this phenomenon, go HERE:

https://www.lexaloffle.com/bbs/?tid=36227