It’s Like @2x for Color
At any rate, I filed it this past summer as radar://41731847: Mojave does not support writing 16bpc/deep color HEIC images.
The format supports it, and we’ve got DP3 color profiles on iOS and MacOS now. We just need the encoders to catch up.
Ironically, the introduction of a wider color gamut such as Display P3 will increase the amount of banding in our images, unless you move from 8 to 16bpc.
Previously: Improving Color on the Web.