Ok, I just didn't explained it good enough. I know that you need monocolor sprites and layer them. The idea would be, that you can pixel it, like there is no limitation, example using 5 colors same time. Finally, the tool would examine how much sprites it would take.
It's ok, if you don't like the idea and not able to do it. But a lol isn't needed in this case.
Viewing post in Spred64 - C64 Sprite Editor V1.44 comments
I saw a C64 sprite editor that can do that. https://csdb.dk/release/?id=143682