How to manage common gui colors in editor and game?

Hi, I have some common colors in my menu, for example:

1. button color

2. text color

3. header text color

I need to put these colors in one place (for example class MenuColors) and i need something that automatically changes color of every gui object on scene when one of common colors changes.

It must work in editor and in game. What is the best way to do this?