YTA - you wife is trying to make your home a nice place for your family to live and for your kids to grow up. While I don’t disagree with you that deciding to repaint the whole house after 6 months might be a little nuts, my guess is she has nothing to do but take care of the kids and wants an outlet for her energy in the form of a project. It’s a form of nesting, especially for women with babies. Why not compromise with her? Offer to help her paint on the weekend but during the week say you don’t want to because you are working. That way you can take turns keeping the kids entertained and painting, it will get done way faster, and you will feel like you collaborated on this project together.
It’s not you vs your wife. It’s supposed to be the two of you vs the world. And it’s an old fashioned idea, but there’s something to be said for the old adage “happy wife, happy life”