To properly enjoy HDR (High Dynamic Range) features on your PS4, please ensure you have the following:

2K or 4K HDR capable TV that supports the HDR10 format.

PS4 connected with a Premium HDMI cable.

HDR enabled content such as a game title or streaming video service (HDR setting may need to be enabled in the in-app menu).

PS4 updated to system software 7.0 or later.