Reds tend to fly more gracefully and slower than other Swifts as they become longer. Their flying style and their conspicuous color makes them a target to the flying predators. Therefore their length must be checked by mating with shorter birds.
Moracca ( white primaries) and Ahmar Gohzar are the same group of birds. Moracca are harder to breed for.
At the bottom left a male Morracca from the above pair that is two years old. The color appears to be fading because of poor light conditions as the picture was taken. By the same token the Red below the sketch is over exposed. I will try these pictures once again with more birds in this department. The point here is the beak setting and the breadth of the forehead and it's fullness.