Shadow of the Colossus looks really amazing on PS4 on my 1080p HDR display. I've been playing my PS3 for sometime as well and the thing I notice most besides the lower resolution and graphics of games is the lack of colour depth. PS4 games without HDR suffer from that issue as well. HDR really brings out the colours in a game and make the lighting and textures feel more impressive than on an SDR display.
That begs the discussion of which game does HDR the best. The thing I talked above is true for some games but just having HDR 10 support doesn't make the colours pop. Games that were released in SDR and later got HDR support like Infamous: Second Son don't look as good as the games where the devs already knew they were going to have HDR during development. Still though some developers just do it better. I'd say GT Sport has the best colour and lighting in a game I've played.