How do I change piece color in edit position?

It doesn’t really tell me.

Not

Trust me, I tried every possible direction, speed, and movement. You just can't. But I have a solution, even if it's tedious, it works. Use "Symmetric Editing". Tap on Symmetric Editing when you're in Edit Position, it is at the top of the list I think. Then you put your White piece where you want your Black piece, then you switch the Black and White piece around, disable Symmetric Editing and then delete the White piece. For 4 player chess this is gonna be even more tedious, but I have a better, more permanent solution. On phones, trying to change piece color in edit position doesn't work (from my experience) but I kind of remember that, on my tablet, it worked! So either you try Symmetric Editing or use a tablet or computer.

It just says click and slide to change color

Yes you hold over the piece and slide