How come when you buy a blue colored shampoo the lather is always white?

You ask the very provocative questions. I mean why is a circle round? My guess is that it gets watered down and changes phyically due to oxidation when it gets suddy.How come when you buy a blue colored shampoo the lather is always white?
Interestingly i think every colour lathers whiteHow come when you buy a blue colored shampoo the lather is always white?
Probably for the same reason that blue toothpaste makes a white lather........





thank goodness.....would give a whole new meaning to bluetooth, wouldn't it????