Powder turning purple

[DorsalSpine]

Why does the FAS-DPD powder turn purple over time? Usually by the end of the season the powder is clumping up and turning purple. It still seems to work ok. I'm usually getting low by then so I just replace the kit with new every year. It is stored in a detached garage all summer. I do bring everything in when it turns cold.

 

[mknauss]

Humidity, etc. It is best to keep the kit in a climate controlled area. Most garages get pretty warm in the summer.

 

[Texas Splash]

The powder will slowly go from white to grey before purple. Grey is still okay, but once it gets purple, it's time t o get anew batch.