Delilah is our first dog with A white face and the same thing happens to her it used to worry me, the eye without the patch around it get really red sometimes?Tess, what you're likely seeing is an increase in blood pressure. The better the circulation to the area, the more pink it's going to look on a pale animal.
I find this to be true across the board with fair animals. I own three dogs with alot of white on their faces...and almost every time they get worked up, their muzzle goes red, their eyes become more pink, etc. Same applies to my red/cream sphynx.