Yes. You can do that in the way I suggested.
You could for example create a modifier (see Writing Modifiers - A* Pathfinding Project) which removes all nodes (and points) from the path after it the first time it encounters a tag. Remove everything in the path.path and path.vectorPath lists after the first index where path.path[i].Tag == yellow.
You will also want to adjust your seeker settings to assign a very large penalty for traversing the yellow tag.