To those who may be confused on how you even color the brain/beginners.

It's very simple. Right click the model and click "Add Override Materials". This allows you to edit the models materials like changing phong brightness, applying color, or changing the textures itself.

Right click the model again and hover your mouse over "Show Element Viewer" then click "Model". There will be many textures relating to the brain. Select any of them, right click "Add Attribute" - "color" then type "$color"

And you are ready to customize the brain to whatever colors you like.