CB311 733T shows colours as if it is in 16bit mode (no fluent colour gradients)

JVDV

Just bought a 733T chromebook for my son for school as it is rugged and chromebooks are used by the school already. Pretty neat little thing the 733T but it bothers me enormously that the colours are shown as if it was in 16bit mode back in the days of windows XP and earlier. So any colour gradient is shown in steps. 
At first I thought it was the screen, but then I hooked up the laptop to a USB3 displaylink adapter and an external screen which showed the same result. The displaylink adapter and the screen are used on a daily base with my Win10 laptop and work just fine. So I guess it's either a shortcoming of the ChromeOS, or an issue with an acer specific setting or driver. Can anybody help?

billsey

CB311-7HT maybe? The display is 1366x768 and should support the normal  number of colors. I wonder if ChromeOS has a mode that drops from 24bit color to 4 bit color as an option for faster gaming or something...