It’s a bit of a project but I can share my code which will give you a huge head start. There are good amount of people using it on a K1 too

The code the creator gives you is not great. It forces you to use filament 1 first even if it’s not present in that print. I fixed that and other things, made it swap colors 4x faster

If you have no plans of getting another printer and love your K1 I think it’s a great idea to just put an mmu on it