Display colors/vibrancy should not affect external displays

[Tech-How]

Your system information

• Steam client version: 1719259903
• SteamOS version: 3.5.19
• Opted into Steam client beta?: No
• Opted into SteamOS beta?: No
• Have you checked for updates in Settings > System?: Yes

Please describe your issue in as much detail as possible:

The Steam Deck has a slider to adjust the color vibrancy, ranging from Native, sRGB, and Boosted. I have the LCD model, and prefer to keep the slider on Native for handheld use. However, when connecting to an external display, the color is now not native to the external display, despite the slider reading so. It is de-saturated below the display's native gamut. This requires the user to manually adjust the display colors each time they dock and undock the device.

Solution:

The color vibrancy slider should only affect the internal display. It does not function correctly or accurately when it's used on an external display. This was the behavior prior to the slider being implemented a while back.

Steps for reproducing this issue:

1. Set the color vibrancy slider to Native on an LCD unit.
2. Observe the color vibrancy, then connect it to a monitor/external display.
3. Ensure the monitor/display is set to sRGB, and does not have any artificial color boosting or contrast enhancements enabled.
4. Observe how the output is de-saturated on the external display, while not on the internal display.