I had radiation for 3 weeks and used Aquaphor either once or twice a day. It is very greasy so I'd put a small amount of saran wrap over it to try to minimize the stain to clothing. I had a slight darkening of the skin about a week after treatment ended - but that was all. I wasn't tired.

It may also depend on the "grey" level you'll get in addition to the type proton vs photon. I had 3D photon and had a total of 40 grey over the course of the total radiation treatment - so it was small portions (centigrey) each treatment for a total of 40 grey.

I also am Hispanic so that might also attribute to the impact to my skin - as I have a slight olive tint to my skin.