Nandrolone phenylpropionate, NPP
You need to drop only tiny amount of the test substance into the vials. There is no initial color change in vial A, changing later to orange and the color in vial B is orange. The initial color in vial A will let you to distinguish right away from nandrolone decanoate. Watching the color under normal light will not give you conclusive results. You need to watch vial B under UV light only when you see the green fluorescence only then you know that you have nandrolone phenylpropionate.
It is simple pass or fail test. Any discoloration under day light will mean that the sample contains other chemicals.
Nandrolone phenylpropionate under UV, greenish color