I'm not a professional baker & I'm making a luau theme tiered cake (10in & 8in) for my daughter bday. 10in will be a butter cake with pineapple filling & the 8in will be a strawberry cake with strawberry filling. My ? is, I would like to frost the 10in with cream cheese buttercream icing to go with the flavor of the cake & filling, but does that mean I have to decorate it with a different icing?  I plan to decorate the bottom cake with a green fondant hula skirt. The top cake with a blue or pink icing with fondant accents of palm trees. I hope I explained it well or even make sense for that matter. 

Depends on the recipe for the cream cheese frosting. I use my recipe for filling, icing and piping. If I had to make a skirt, I'd use the grass piping nozzle and just add a bit of colour in some frosting in a separate bowl. Hope that answers your question. Good luck with the cake and happy birthday to your daughter!

I believe I've found a good stable cream cheese frosting thats pipeable just havent tried it out yet. To pipe it would probably be best too bc fondant is definitely not a strong suit of mine just yet. In order to pipe the grass skirt would it be best to pipe fom top to bottom or bottom to top? & thank you

top to bottom -- I'd use either a #2 or #3 or a grass tip

I disagree  it's easier to pipe bottom to top as the 'skirt' is going on the cake itself and not a figurine  then you can tidy up the top with a ribbon or just a line of differently coloured frosting  no idea what happened to my phone  full stops have disappeared apologies