Aluminum screws, no matter what the color are a waste in most applications. The weight savings is very small and the durability of the screws is nill. They are fine for low stress applications that don't get removed a lot: Servo mount screws, transponer mount, wire hold downs, wing mounts on the body, etc.
NEVER use them for any critical mounting points - Shocks, suspension, transmission, etc.
Most of the plastic we use in today's cars is stronger than the aluminum screws available.
What good is saving a .1 oz of weight if you don't finish a race because your car is setting on the sidelines broken.