Does anyone know this movie?

I need help identifying a movie I saw as a kid. Nobody has ever been able to figure it out. In advance, no I did not dream this up.

Here's what I remember:

It was an 80's/90's sci-fi action movie.

It involved evil aliens who had infiltrated Earth and looked human but had yellow blood. There were 2 that I remember, a man and a woman. The woman was blonde and I remember Sarah Connor vibes from her.

There was also a good alien and he had blue blood. He was played by a black man and worked as some kind of CIA/FBI agent. White shirt. At the end of the movie I remember him being wounded and bleeding out but he lived.

The main protagonist was human and had a kind of biker Hulk Hogan Dog the Bounty Hunter kinda vibe. Pretty sure he had a motorbike.

The end of the movie was a shootout in some kind of large stone building and culminated in one of the aliens getting thrown/launched outside and they got impaled on the American flag.

There were obvious sci-fi elements like the aliens and their different blood but it played out much like an action movie with regular guns.

Please any help would be hugely appreciated. I've been trying to identify this movie for like 20 years and it's tearing my soul apart not being able to. It's quite hard to search about because certain elements of it massively point to other movies.