I have this issue as well on my surfacebook 1 purchased in October, 2016. I never used the laptop outside, but decided on a sunny afternoon to use it under a covered patio in indirect sunlight and noticed the discoloration begin. Immediately put it cool temperature under a fan, but too late, the yellow streaks on all three sides of the bezel 1 inch long are permanent. I spoke with MS support, it is out of warranty, they can only offer a replacement for $810 CAD.
If anyone has any more luck, please post.