This is it. It’s why seats/stools look nice but feel uncomfortable after 20 or so minutes.

It’s a natural stage of development. Playing with the idea of reality is part of understanding and accepting the world around them. Let them play in the world of make believe while asking them about what they’re experiencing and help them form understanding. *Pointing to blue item “This is orange.” “That’s orange? What else is orange?” If they demand you agree with them, it should be fine. This is early development. It’s way, way more important that they feel safe and loved than what they’re thinking and saying. They will grow and if they seem to be too distant from reality, there’s plenty more things you can do to help them at that stage.