This is a touched up version of the endgame map of a Portugal campaign in Europa Universalis 4. To create this map, I took the built-in map screenshot, then selected only the regions owned by myself or my subsidiaries.
Then these regions were copied into a new layer, and the original layer was flattened to just land and water. The owned regions were then given a darker border. I then added the flags from this imgur gallery, and gave them a black outline.
Finally, I added the labels, title, and the Portuguese crest, completing the map.