Didn't know PS5 (and XBSX?) outputs 120Hz games as YCbCr color space instead of full RGB, apparently because of bandwidth limitations.
That's why you should not force your TV at High/Full black level, but use Automatic instead.
yep, Vince had video about PS5 bandwidth limitation about a month ago. XBSX can do 4k/120Hz in RGB without problems.
and yes, most TVs have working auto detection so automatic is fine.