Yes, HDMI is 24bit color (8bit each for RGB).
As said, your display uses FRC, so your controller board will use any input.
Maybe you should mention which hardware you want to use
Btw: here is what a 4k desktop looks like https://www.raspberrypi.org/forums/view ... 3#p1491361
Full image https://drive.google.com/file/d/17K1S4m ... sp=sharing
The display which I'm using is a Sharp 31.5in UHD, connected to a Digitalview SVX-4096 controller
Look af the controller spec here https://www.digitalview.com/controllers ... oller.html
where no of colors is of interrest for you: upnto 10-bit per color
So again, yes, it's possible to use FRC 10-bit displays