Most recent build of Start10, fully updated windows
If you switch to a 2nd user in windows 10, and then switch back to the original user Start10 inherits the colour from the 2nd user
Even if you sign out of the 2nd user before switching back, the colour is still switched for the original user
Selecting reset to automatic colour within the appearance menu doesnt fix it either, and only a reboot will
Hope that makes sense!