Chroma subsampling

Chroma subsampling reduces the color detail stored or sent with an image. It keeps fewer samples for color than for luma, the signal's brightness-related component. You may recognize the labels 4:4:4, 4:2:2 and 4:2:0. Of these, 4:4:4 keeps full color sampling. The other two reduce the color samples. Apple’s Y′CbCr note

BetterDisplay shows these labels as part of supported color modes. They describe the signal. Choosing a different sampling format does not itself change the desktop space available for your windows.

Fine colored edges can look different from grayscale detail when sampling changes. Choose a mode supported by the complete connection between the Mac and display. A label alone does not guarantee a suitable result.

See Color Mode for the related options.