New to 3D Printing - Need help diagnosing print problems

[jurban]

Hi there, I recently started 3D printing and my first project is a series of tiles to use as decor on a blank wall. The print is a very simple rectangle with some flanges to connect to the housing. What I am running into is the print will seem to not be as dense, almost as if it is skipping paths. I have printed multiple colors and some colors print perfectly, others have this issue of missing filament. I have attached a picture of what I keep running into. I really appreciate any and all feedback to help diagnose the issue, thanks!