This sounds like very odd. I tried recreating the color changing behaviour in Tableau Desktop 10.1.1 but my colors remained the same after I exported the .twbx.
I recommend upgrading to the latest version if you're not already running Tableau Desktop 10.1.1. If that doesn't resolve the issue, then you may want to open a support case to troubleshoot the issue.
thank you very much! I already use 10.1.1.
I think, I will contact the troubleshoot.cracks
Has this issue been solved yet and if so how did you fix it?
I have the same issue as you did.