Sony FX 6 Quick Start Manual page 45

Custom Shooting Mode: Base Settings
In Menu/User/Base Setting pick SDR (BT.709) for the Target Display.
This guide only covers shooting in the Rec.709 colour space, called SDR(BT.709) in this
camera. The majority of display devices in the world are Rec.709 devices.
HDR(HLG) target display is chosen when you are shooting for extra bright HDR TVs.
There will be a separate guide on shooting HDR and dealing with HDR in
postproduction.
Then in this menu, or in the status pages, pick the Custom Shooting Mode.