WPF Triggers - Pain Points

I have a very big control, which in-turn contains lots of small controls hosted in it. Previously, we were applying themes using VisualTree iteration. We planned to replace the logic with Triggers. Now, when w开发者_Python百科e apply any theme it takes much time than the previous implementation. [For example, previously it took around 100ms now it varies from 1-2s]

My question is this. Is there some thing we should avoid while using Triggers in WPF? or Using Triggers for such a big project for applying themes is a bad idea?