Actually, in brine shrimp the red color is a sign of oxygen depletion.
It all depends on how well you feed the brine as to how nutritious they are. Brine shrimp are indiscriminate filter feeders, meaning they pick up and eat everything that's the right size, without regard to it's nutritional content. This can be a bonus, in that if you think your fish need a suppliment of some kind, you can feed it to the brine a few hours before you feed the brine to the fish. The supplement will be packaged up in prey critter goodness.
I personally would rather hatch and raise something native to the waters your fish are from. Look for rotifer eggs, available in some of the same places as brine shrimp eggs.