HDR Display Issues with Overlay

[Bioanalytica]

It's not possible to use SteamP2P with HDR enabled because the display becomes super bright and washed out, disabling HDR fixes problem.

[tremwil]

This is weird as the overlay window is a WPF window, which should have HDR support. Sadly, I don't have an HDR display to test this so I'm afraid I won't be able to fix it unless someone has more detailed information.