This likely is related to background texture color coming through when zooming out and is called mipmapping. See related post. Tldr try to overpaint your UV islands with a border of the texture main color of approximately 2-4 pixels wide (it doesn’t mean you need to invent 2 px wide brush, the end result should look like that). Or shrink the UV islands.
On a side note, paste the files (screenshots and blends) directly into the post please so that they aren’t lost after sometime somewhere else and don’t require going through links to look at them.