So, I spent all week making pink and orange flat fondant birds for this cake. The cake is covered in light blue buttercream and MUST be refridgerated because of the filling. Can I put my fondant birdies on the cake and put it all in the fridge? Or will condensation take over and cause the colors to bleed? Anyone have any experience with this?

I've never had a problem putting a buttercream cake with fondant decorations in the fridge. Just make sure you are not using a ton of water to attach the decorations.

I do fondant decorations on buttercream cakes all the time. I have found that you have to cover the cake to keep the condensation off the cake in the refrigerator. I have a large walk-in with pretty low humidity. I still keep every finished and decorated cake covered in a box in the fridge. I bought big cardboard boxes and keep wedding cakes in those.
The cake sounds cute. I love birds on cakes!

I'm having the same issue...I'm making a cake with chocolate ganache filling, and I'm sure it won't be wise to leave it out. My problem is that it will be covered in total black fondant & I can not take a chance with wet spots or other condensation issues.
I've heard that putting the cake in a cardboard box, not cake box, will keep cake refrigerated without damaging the cake.
I appreciate any help with this because I don't want to mess my cake up, but I don't want the filling to go bad. Also, will refrigerating the cake make it stale? thanks again for any help!!!!