What i mean by pink dye is where the test and control lines are. Those are in blue which means its blue dye. The pink dye you are referring to only shows up when urine contacts it because it tells you its working. But the actual dye used to tell the result is blue as it shows for the test and control. There are tests where those lines show up in pink. Most dollar store tests or first responce are pink dye tests. Clear blue ones are blue dye just as the name says
Using one with pink dye just helps to confirm the blue dye isnt showing an evap