From what I have found on the API site and a post here, the liquid test fluids for ammonia can be used for both fresh and salt water testing.

Is this correct? The saltwater colour chart is posted on the API site for both salt and fresh water so I can compare there is the is a variant in shades.

If this is correct, I just tested my 55 gallon and I'm at 0.25 ppm.

(Note; there is only uncured live rock in the tank. I'm just starting the cycle process.)