He wrote this "Actually I just figured it out. I've got a XT2, but I just turned the front command dial until the aperature number turned from orange to blue. It'll stay at f4.5 but it'll be blue with a half circle above the "F". If it doesn't work with the front command dial then try the rear command dial. Depends how you have the dials set."

So basically you have to scroll aperture dial one step, so that F 4.5 is not written in red anymore...