I want to invert the colors of a texture brush. How can I do that in Blender without using an external program?
You can use Texture node, which is supported by the texture paint system, too. Actually, it can be much more powerful than just inverting colors.
- Open a Node Editor. In the header, switch the Node Type to Texture, and the Data Type to Brush;
- Add an existing Texture or Image node, link it to an Invert node before Output. As shown below.