colors morphing on visualitations

why are the colors I choose for data item/axis changing without me doing anything?

In short, I set the colors, go to "reading view" and save, logout, then come back 1-2 hours later, and sometimes the colors are different.

Also, when I change the colors of one viz (in order tomatch another,) sometimes a 3rd viz on page gets changed without me doing anything.

what a pain. what is going on?

PS. this is on BI service. I am using IE11.