How do I fix the STEAM background color to normal?

[JOYJOY(Owl_lwO)]

I think the background color of the STEAM that you and I usually saw is black or bluish black, but since today the background color of my STEAM is strange.
It has been synchronized with the OS system color.

I am a person who finds the whites of monitors extremely glaring, so I use the high contrast mode to eliminate whites and bright colors as much as possible.
However, in that state, the background color of steam changes to gray, the background color of the system.
If I return the theme from high contrast mode to the default, the background color of STEAM also returns to its original color, but in this state, other explorers, etc. are too bright for me to use!
How can I return the background color of steam to normal while still using the high contrast mode?

[cSg|mc-Hotsauce]

Make a bug report... https://steamcommunity.com/groups/SteamClientBeta/discussions/0/