Disable color management toggle when off flickers the gamma in gaming mode with mouse movement on external display

[Sunspark-007]

Your system information

• Steam client version: 1749753892
• SteamOS version: 3.6.24
• Opted into Steam client beta?: Yes
• Opted into SteamOS beta?: No
• Have you checked for updates in Settings > System?: Yes

Please describe your issue in as much detail as possible:

SteamOS developer settings contains a toggle for "Disable Color Management" to allow everything to be purely native.

When the deck is docked and connected to an external display and no inputs are happening, the picture appears normal. On mouse movement the gamma becomes very dark and upon cessation of movement the gamma returns to normal.

The gamma should not be changing when the mouse is moved if "Off" is set.

This fluctuation does not happen in desktop mode, only gaming mode.

Having colour management on for gaming mode likewise does not cause this but I am suspicious as to what values it is really applying for vibrancy and color temperature on an external display.

Steps for reproducing this issue:

1. "Disable Color Management" toggled to on in the developer settings on the LCD deck.
2. Dock the powered off deck and power it on connected to an external monitor.
3. Observe normal display, move mouse, observe screen gamma become dark. Stop movement and observe screen gamma return to normal.

[matte-schwartz]

that's expected behavior afaik. if you want to only have your EDID driving color management then in Display settings you can enable Use Native Color Temperature

[Sunspark-007]

Is it really expected behavior to change the gamma every time the mouse moves and then put it back to where it should be when movement ceases?

In any case, use native color temperature has a gamma issue of its own as well compared to selecting a temperature of 6500K so I have created a second issue for that as it doesn't involve disabling color management.
#1991

[matte-schwartz]

Yes, Gamescope is compositing whenever you move the cursor so removing all color management in the pipeline results in the type of image you're seeing.

[Sunspark-007]

This makes sense, thanks.

Follow-up question: why doesn't this behavior occur with the internal LCD panel?

[phly95]

As per the Bazzite Discord, it's possible to disable the flickering by enabling the "Force Composite" option in developer options. https://www.answeroverflow.com/m/1355280018741395496