How to remove or cover up splatter painted walls?

Did you try painting over the walls with a textured interior paint? You can buy a really great on at Lowes made by Valspar.

Choose your favorite color of paint, a new roller, and paint over it!

Easiest is to paint over them. Remember prep is the key, wash, prime, paint.

Since the spatter is sitting above the flat paint, you will need to sand it off before you repaint. After the wall is smooth, you can put on a coat of primer, then paint as you wish. An electric hand sander is probably the best so you can focus on splatters, but a larger sander if the spatter is all over the room. Best wishes ☺️

Instead of sanding to get a smooth wall you could a) skim coat the wall with joint compound, or b) Kilz has a new primer called High Build that can smooth out texture and then repaint.

Kilz... http://www.kilz.com/MCContent/MC_Product/KILZ/KILZ_TDS/HighBuild_TDS.pdf

skim coat... https://www.youtube.com/watch?v=jeGWbgAUvCM&t=107s you can see further down under comments a link on how to prepare the joint compound and tools that he's done too

YOU CAN PAINT OVER THE WALLS BUT IF THE SPLATTERS ARE PROUD, THEY WILL SHOW THROUGH AS A TEXTURE.

Paint over. However, if the splatter is textured, or raised, paint won't cover.