Why are my white mums turning purple?

After googling, I found that they're not just turning purple because they know it's my favorite color (I know, not funny).

Here are some reasons why your white mums may turn purple or pink ...

-mums change color as they age (before they die)

-mums change color according to the pH of the soil 

-mums change color as the weather gets colder 

Personally, my color is affected by all of these things too.  Mums, I totally get you.