Assuming the content you stream has HDR , it should. If it doesn't you won't. Unless the Apple TV has some sort of bug, I don't own one, not a big fan.
Media room- 65" Panasonic FZ950 OLED, Pioneer Elite VSX-90, Panasonic UBD-820 4K, Klipsch Gallery G28's, Klipsch Sub 12, Klipsch RS-52 II, Optik HD cable
Living room- Sony 4K 79XBRX900B, Onkyo RC-360,HTPC,Klipsch Reference R-62II,Rc52II,PS4
Gaming room -Panasonic ST60, PS3, Wii