While I may be a total newbie to trad archery, I do know a bit about camera's
This is a common issue with smaller sensor sizes in point and shoot camera's as well. Not the number of pixels, but the size of them. The less expensive and older trailcams have tiny sensors and they lose color depth and dynamic range when there isn't enough light. That's why all trail cams turn to black and white as it gets dark.
To fix this issue you really need to step up to the more expensive trailcams. I have a couple of the newer Stealthcam 4K jobbers that do an incredible job relative to any of my older wildgame or Moultrie versions.
In any case, pretty sure it's not something your doing wrong just a case of go time being when your trailcam is going to work at it's poorest.
Cheers,
Pete
vimeo.com/petecarney
youtube.com/user/c3hammer