when the display tint changes, the following command got it back to normal
xrandr --output HDMI-1 --set "color_format" "rgb"
this just happens to be the first thing i tried that made a difference, so likely there’s a better way
(i’ve also seen the colors look as they should after powerup when “color_format” is listed as “ycbcr444”)
also, is HDMI out a relatively new thing for NanoPi devices? looks like everything on the R5C is software/CPU driven at this point, no graphics hardware acceleration … in addition to the item reported above, I’m able to help with other testing on the R5C