first, why would youy want to have any hair, thinning or not, detract people's gaze from those eyes?
Second, shaving at this time of year you know there will be a little color difference. But a couple of days with short exposures to the sun it will be gone. From then on your skin will maintain an even color.
I always use a light sunscreen when I am going to be outside for more than 30 minutes. I don't want the sun to damage my face and make me look 80 when I am only 60. I like the Neutrogena ultra shear sprays because they are not greasy, go on dry, and are sweat and water resistant.
I always use a moisturizer on my face; Clinique "M" (For Men) moisturizing lotion. They make a version of this that also contains a light sunscreen.