Ok, in a few weeks I have a wedding order.  It will be a 3 tier cake- not stacked (sitting on a 3 level cake stand). I actually have a few problems with this cake....1 being it is an alien themed wedding LOL and the other being the customer wants butter cream AND whipped.  The bottom tier will be butter cream, middle is whipped and top butter cream.  My question is, how will this even look together as one cake?  I tried talking her out of it because I have a feeling the color won't take to the whipped like it will the butter cream.  My idea was originally to replicate one of those story cakes (only aliens instead of people) and to do that- i was going to use fondant figures for the sides.  Will the fondant even stick to a whipped with out sliding off the cake?   I tried to offer free cupcakes with the whipped icing but she is really set on this.  I honestly don't even have a whipped recipe that I work with regularly because this isn't something I normally do.  My whipped version is a cooked icing that consists of flour, milk and granulated sugar.  Please, any advice on this will really help me  A LOT...or maybe a good whipped recipe that will hold up? I am still new (1 year).  Thank you!   Oh and the middle tier will is only for 5 people!!! (they won't eat butter cream icing) 

AIf you use Richs Bettercreme...which is what she probably means by whipped...you can color it any color you want. You can find it at any cake decorating supply store.

Not sure about the fondant though.

Thank you :) I have heard a lot about that butter cream but I have never tasted it.  The whipped icing I make is similar to a grocery store whipped icing minus that weird fake flavor lol  I added marsh mellow fluff to it and it really tasted exactly like the store kind.  I am just so lost on this cake.....I can get my butter cream pretty smooth but im not sure about this whipped...I am afraid it won't look right as a whole cake

AI bet the normal way of smoothing will look fine. I know lots of people who use the fluff in their icing, and they smooth it like they would any other bc :)