Well, I fought though the funk I've been in for the last week or so and got a goal done. The enemy skin colors are now working. If you have played the original game you will notice that the colors don't seem as vibrant as they used to be. This is because the underlying luma is grey and things are a little washed out. This isn't a problem as the aliens are going to be redone anyway. This means that Gorn, Robbie the Robot, The Borg, The Chicago Bulls, Tholeans, Ninja Turtles, and others will be will be gone.
When adding functions to the game, such as high resolution and alpha blending, I'm trying to keep Allegro code away from the actual program loop. What I have been doing is actually changing the Nermal functions and extending them a bit. For example I added a new type of blit called B_TINT what will copy over bitmaps with whatever color is set in a global tint variable. I couldn't add an argument to the BitBlit() function least it break all the blits in the game. (I counted , there are 891 calls to that function alone.) I just added a mode and I'm taking the extra data from a global. It's terrible and hacky, but it works.
My next goal tomorrow is the master 1Ch thread I keep saying I will do over and over again. When that is complete... I will run the game proper for the first time from end to end and it all should just work. I know there are still filesystem functions in the game proper I need to replace, but the builders, for the most part are functional. They are not "done" by any stretch of the imagination. The graphic update in Phase 3 is going to pass over those. I also need to add an options button and implement UI themes.
But, it would be nice to play a mission in the actual game first.