Question: Blue Dye Pregnancy Test

Alice • 19👽 ♎Libra/Virgo♍ Cusp🔁 😊Happily taken🔒 by my bestfriend🗝️💕6/26/17

If blue dye test have a tendency to evap, false positives, be defective, ect. and everyone seems to know that pink dye test work much much much better. Then why do they still sell blue dye test?