Combined gamma slider option

[fff7d1bc]

Hi,

Would you consider adding combined gamma slider an option to make it possible to adjust gamma of all 3 gammas at the same time? I found the VibrantDeck Gamma settings Red/Green/Blue to be a life saver when it comes to games that are too dark to play. One of many examples is Bioshock 2 Remastered that on SteamDeck have not working. By setting all 3 gamma sliders from 100 to 250 I can finally enjoy the game on Steamdeck.

I came across this feature by accident, seeing that it has gamma sliders. For people that are visually impaired the ability to bump all the gamma settings is must have so adding a single slider for it would be great to have

[arianneorpilla]

Would also be useful to have a boolean option for toggling adjusting the gamma (as I consider saturation as an "always must have on", and gamma as a "need only sometimes"), below the boolean option to enable or disable Decky.

A good use case would be to read something in really low light, and you want a game to display darker colors than the lowest brightness setting already lets you. Sometimes I would put all gamma values in values of 3, 4, 5 from 100 when I am reading in really low light. Some games don't let you adjust the brightness/contrast setting and accessing it via Decky is just tremendously useful.