The color space and HDR metadata are eventually sent as metadata to the
display. The color space informs the display of the colorimetry of the
frames we produce, the HDR metadata informs the display of the transfer
function and additional mastering display colorimetry and luminance to
guide tone and gamut mapping.
The only color spaces we support right now are the default color space
and Rec bt.2020 which is typically used for HDR content. Other supported
color spaces can be added when needed.
The default color space corresponds to whatever colorimetry the display
has when no further changes are made to the calibration of the display.
The colorimetry is communicated to sources via EDID/DisplayID.
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2879>