Upgradable Plants showing in Imitator colors!

I was playing Survival Endless when I noticed several of my Upgradable Plants (Cob, Gloom, Winter, etc.) were showing in the greyed out/darker Imitator color!  How is that possible??

You cannot select any of them via the Imitator so something in the game must have re-colored them?

I attached a picture.  Game play was normal and it was not causing any issues.  Just reporting the anomaly!