You can see quick change from yellow to light orange to dark brown in a few minutes in both vials A and B. The fluorescence under UV light in vial B is very distinct bright green. You can also notice green fluorescence in vial A, which disappears later. The fluorescence in vial B will hold for a long time, you can see after two days that there is still green fluorescence but not as bright as it was.
This is for example different from nandrolone decanoate; in this case you will not see any green fluorescence in vial A. But there is noticeable difference in vial B, trenbolone ace gives brighter green, while nandrolone decanoate appears as darker mat green.
There are two different test agents in each vial, which will react in different way to different chemicals. Any discoloration in vial A or B will also indicate presence of contamination. This is why you need both test vials to confirm presence of steroids and their quality. Some steroids will give different initial color in vial A. For example the initial color in vial A for testosterone propionate will be olive green while for testosterone enanthate orange. This is how you can distinguish them. Now you probably wander how to distinguish acetate from enanthate, leave the sample for 24 hours, acetate will appear more yellow while enanthate still holds to the green color.
Trenbolone acetate, oil left, powder right, initial colors just after dropping the samples.
Trenbolone acetate oil under 365UV light, vials A and B
Trenbolone acetate raw powder under 365 nm UV light