Learn how to use the new Texture Color tool in Unreal Engine 5.5. It can be used with both nanite and non-nanite mesh instances. The new Mesh Paint material nodes should be used to be able to make it work. This video is a deep dive into these topics.
https://dev.epicgames.com/community/learning/tutorials/JZxm/texture-color-tool-in-unreal-engine-5-5-mesh-painting-on-nanite-meshes-deep-dive