HDR is supported but there's no option to enable/disable in the video settings. It needs enabling from the desktop first. Can I amend the video settings section to reflect this?
Talk:Forza Horizon 3
Quite recently I found following note: " Note that Windows 10 v1803 ("April Update") and later performs automatic tone mapping of SDR content when HDR is enabled, which is not the same as if the game natively supported HDR output. To see if that tone mapping feature is being used, play around with the Display settings > HDR and WCG settings > Brightness for SDR content while the game is running in a window. If the brightness of the game changes then it outputs in SDR and does not support HDR output natively in window mode. However if the brightness does not change then the game properly outputs in HDR." https://www.pcgamingwiki.com/wiki/List_of_games_that_support_high_dynamic_range_display_(HDR)
Could you check whether the game supports real HDR and not automatic tone mapping of SDR content when HDR is enabled? I assume you have W10 1803 or later, right?
Forzamotorport forum seems to confirm this. I think yes, and it's great news. I didn't know about it. Thanks