Several times a week when switching from one streaming app to another, I get a almost totally teal green double image of my Home Screen. I have to unplug the Roku devise, then plug it back in (reboot?). Following this exercise the picture returns to normal. Only to happen again a day or two later.
Model number???
If you are using MicroSD memory pull it out.
You can also try lowering your Display type to 1080p or 720p.