I have the same issue on MacBook Pro 15 “ model from 2017.
View attachment 881096
Horizontal lines are flickering and changing color. It started the next day when I opened the lid.
Connecting external display works without flickering lines.
I wonder if this happens more often for this kind of model ? Seems that not only the 2016 MacBook Pros with backlight issues are effected. So the message is, don't close the lid it can damage your display.
My old MacBook Pro from 2010 still works. Only changed the battery once.