I am experiencing some problems with HDMI wrong colors. It happens on all meson boards I tested (lepotato, c2, and a custom build for Khadas Vim2).
It only happens with certain monitors/HDMI adapters, others work fine. In addition, I cannot select other resolution than the default (in this case 1280x720).
I think the problem must be in u-boot hdmi initialization, because it is also present during the armbian boot logo. The problem happens in framebuffer console, Armbian boot logo, and X session with fbdev driver.
These are some screenshots of the failing displays: https://imgur.com/a/fW7lskz
This is something similar to what is reported for Odroid C2 in HK's images: https://wiki.odroid.com/odroid-c2/troubleshooting/forcergb , I am not sure if it is related.
I narrowed it down to be the framebuffer having trouble with setting the right parameters, things work fine when you start an X session with some driver other than fbdev. I updated title accordingly