Chroma subsampling

Chroma subsampling reduces the amount of color-detail information stored or sent with an image compared with its luma information. You may recognize the labels 4:4:4, 4:2:2 and 4:2:0. Of these, 4:4:4 keeps full chroma sampling; the other two reduce the color-detail samples. Apple’s Y′CbCr note

BetterDisplay shows these labels as part of supported color modes. They describe the signal, not a new desktop size: choosing a different sampling format does not itself change the logical 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, rather than assuming a label alone guarantees a suitable result.

See Color Mode for the related options.