Color Mode Problems (Macbook M4 + external Dock + 2 Displays)

[Leon336699]

Hey there,

I am using a Macbook 4 with an external dock and two external displays. I just read about the problems regarding color modes (YCbCr chroma subsampling vs RGB).

If I connect my MacBook to my dock and connect the first external display via USB-C I can get full RGB:

If I then connect the second display via Displayport I also get Full RGB with my second monitor.

Both monitors work as expected and the colors look good.

But as soon as I reboot my MacBook or switch my dock on/off, the first display goes into YCbCr mode again. The problem is that I can't change it again in the settings because I only see one option:

Configuration Protections doesn't work either. The only solution is reconnection the displays one after the other (like explained above).

Is there something else I can try?

Regards

[waydabber]

Lack of options are usually due to bandwidth constraints. Is that at 60Hz? If not, try lowering the refresh rate so more bandwidth is available for higher color modes.

[Leon336699]

Yes, it is 60hz. But it can‘t be real constraints because everything works fine if I connect one display after the other? And is this a macOS problem or dock problem?

[waydabber]

Well, if it works properly without a dock then it is probably a dock issue.

[Leon336699]

No, both screens work in full rgb and 60hz connected to the dock at the same time. But only if I connect one after the other. So the bandwith in general should be fine (the used dock is a thunderbolt 4 dock). It’s somehow the negotiation process between the mac/dock/displays after a reconnection thats the problem.