Which dye test is best?

Everyone has told me trust the pink dye and not the blue dye EVEN if the pink dye shows a faint positive and the blue dye is a negative. My question is why is that??? Is it because the pink dye is more sensitive than the blue?? I got 3 VVFL on a pink dye tests and a negative on a blue dye test and I’m not sure what to even believe anymore or what to think 😞 I feel so confused