YouTube has steadily been improving picture quality with 4K, HFR (high frame rate), better encoding, and even 8K. The streaming giant will start supporting HDR (high dynamic range) later this year.
HDR on YouTube
The news was announced at CES 2016 during LG’s press event. LG says that its OLED TVs will start supporting HDR content from YouTube later this year.

LG is not the only company that will support YouTube in HDR. Samsung and Hisense are also showcasing YouTube’s HDR streams on the show floors of CES 2016.
To deliver HDR through YouTube, Google has had to further develop its VP9 video codec. To date, VP9 has not supported HDR but with VP9-Profile 2 it will. It is unclear whether 2015 TVs with VP9 support can be updated to VP9 Profile 2. Google also has a VP9-Profile 3 in the works.
We have tried to confirm a launch date but so far everyone involved just cite “later this year”.