Steps to reproduce:
1. Open attached project. (New Unity Project 5)
2. Open scene Test.
3. In Lighting settings try changing skyboxes. (2 and 1)
4. Cube's color changes.
5. Hit the play button.
6. Do step 3 again.
7. Cube's color does not change.

Note: if a cube is set to static, cube's color changes.
Also, if a cube is static - it's color after change has a previous color shade.