Hi,
I hope to understand you right when I read TGW as GWX - in that case this should be absolutely normal. The color coding on the map is something very unrealistic, because it automatically identifies and classifies contacts as, just as you said, enemy, neutral or friendly. However in real life you would have to check visually first, so you'd have to raise your periscope and check for the correct ship type and (or at least) the flag it actually sails under in order to identify an enemy target - all by just using your eyes and cross-checking with the recognition manual.
So, in fact this is a feature that adds to the realism of the mod, it's nothing that would require a "fix" since it isn't any kind of bug at all. Take it as a challenge and a chance.