This was requested by a comment. Not sure how well it will work in based SDXL, but give it a try in your workflow.

I tagged it with terms like "Disco Elysium, abstract, painting, expressionist, abstract background, harsh brushstrokes, colorful background, portrait."

I do not use base SDXL often, so you may be able to get higher quality results with your own settings. If you do, please post your settings in a comment.