I am drawing a simple 2D site plan of our business. I’ve been using Sketchup for this for a year or so but have been having this problem recently. When I go to color certain areas it will randomly color areas outside the selected area. I would love some help and am willing to upload my file for someone to take a closer look at it.
If it is 3MB or smaller you can upload it directly to a forum post using the icon that looks like a little bar with an upward arrow at the top of the post edit window. Otherwise you can put it on a file sharing site and provide a link here.
Unless the faces are not actually closed or there are multiple faces superimposed on each other, coloring one shouldn’t affect others.
As I orbit around your model I see a lot of color flashing (see attached animation). This “z-fighting” is a sure sign that you have multiple faces placed at exactly the same place in the model. The display system can’t determine which should be shown in the view because they are at the same place, so it flashes them as a warning.
Z-fighting for sure, as @slbaumgartner pointed out.
But I’m curious how you got to draw the squares without having them to separate the large face.
It’s part of sort of a bug SketchUp is dealing with. You can heal (=separate) some square faces by drawing a diagonal and deleting it again. Not all squares can be healed this way. It would be better to redraw this part again.