Yes, there is only 1 MAS 8x3. At the request of the RCCA, MAS changed the color of the 8x3 to make it blue to make it easy to visually tell that everyone is using the correct prop.

However, there are still some black MAS 8x3 props out there that haven't been broken yet. If you have them, they are legal, and you can use them. You get have a CD check to make sure it's the right prop, but that's the worst that can happen.