This is a really easy and straightforward one. First you run your game, then go to options in the main menu, find Save/Interact and on the bottom you have the option called "Enable Console", which you need to have on Yes in order for this to work.

After you have done that, press the ` button on your keyboard (the button next to number 1 to your left) to open your console and then type in or copy-paste the following line: r_ignorehwgamma 1

Once you have done that the console will say r_ignorehwgamma will change upon restarting. After that just quit your game and start it again. You won't be having that strange contrast/brightness in the main menu or the steam overlay anymore :) You can see below 2 screenshots which shows the console and the whole process.

r_ignorehwgamma 1

r_ignorehwgamma will change upon restarting

As most of you have experienced the issue in the main menu and the resolution I will now help you in fixing that. The important thing that you need to remember is after doing this don't try to change your resolution in game as it will mess everything up, meaning you don't need to change it in game at all.

First of all you need to go to "C:\Program Files (x86)\Steam\steamapps\common\Call of Duty\uo" (for someone is different, but it's usually the path.

After you go there you need to find a config file called uoconfig.cfg and open it with Notepad++

Once you have done that you need to find certain lines with the use of CTRL+F and just change them to these below:

seta r_customwidth "XXXX" --> seta r_customwidth "1920"
seta r_customheight "XXXX" --> seta r_customheight "1080"
seta cg_fov "XX" --> seta cg_fov "96"
seta r_mode "X" --> seta r_mode "-1"
seta com_introplayed "0" --> seta com_introplayed "1"

In the end if you liked this and it helped you be sure to rate it up and add it to your favorites :)