Hi! I'm using the default settings and tested it with a brand new sprite as well. Tried unchecking "quantize palette" and still got the colored issue. That happens to small and big sprites.
I'm running it on Linux, which might be the issue. If I try to use the native Aseprite version for Linux, the add-on straight up doesn't work and I get an error window. By using Proton, it gives this weird colored result even though I gave all the access it requested. Do you have a list of the dependencies of the script so I can try to emulate it?
Thanks!