Does cream cheese icing need to be kept refrigerated or will all the sugar act as a preservative?

I'm working on a 3-tier cake, and one of my sister's top flaviring choices was carrot cake with cream cheese frosting.
The decorating on the cake won't be very eleborate, so I'm not concerned about having to decorate with it. I'm concerned about whether it needs to be refrigerated.
Also, will colors mix alright with cream cheese icing?

And for the tiers, I'm thinking of doing carrot cake (top), lemon cake with a raspberry/strawberry filling (middle), and a white cake with an oreo filling (bottom). Will the flavor of the creme cheese icing compliment all these tiers?

Thanks for your help/advice.

Well, technically you are supposed to refridgerate cream cheese frosting. The thing is, I don't, for home use, never have, it is fine for 3 days, the same as any other icing. But when I use it for a wedding cake or any cake I serve or sell to the public, I do refridgerate it if I can, at least after overnight or so. So the sugar does preserve it, yes, but commercial bakeries must refridgerate it.
Confusing, I don't mean to be.
If your room temperature is below 75F it will be fine. However if I was in the U.S. where lawsuits are a very real risk, if I was selling to the public or at any risk of a possible lawsuit, I would be refrigerating just in case.
Hhmn, as to whether it will go with the other cakes and fillings, well personally I only use it on spice cakes, carrot cakes and red velvet.
So what I usually do is use it as the filling in the carrot cake layer and then just ice all of the cake with buttercream. You won't be able to match the outside icing if you use cream cheese icing only on the carrot cake. It is a matter of taste preferences too.
If you are icing the cake on a Friday for a Saturday wedding, I wouldn't worry about refrigerating the cream cheese covered cakes.
If there is butter in your icing as generally there is with cream cheese icing, use salted butter. The salt in the butter is a preservative.
Hugs Squirrelly Cakes

Mmm, I love the idea of those three tiers: carrot, lemon and oreo! Yum. But about the cream cheese...I don't have a ton of experience, but when I've made cream cheese icing and left it out, it doesn't seem to keep very well. (It could just be my imagination, but it tastes a little rancid after a few days.) Also, I don't think cream cheese would compliment the flavors of the other two layers very well. I like squirrellycakes' idea to use cream cheese as a filling for the carrot tier, and then do the exteriors in buttercream/fondant. A great compromise!

Thanks for the tips. The cake is for my sister's baby shower. So I'm not worried about selling it to someone who might sue me, but I also don't want any of my family to get sick. With a LARGE extended family, I'd NEVER hear the end of it!

For some reason, I hadn't thought about just using the cream cheese as the carrot cake filling. I like that idea and think I'll go with it. That will save me a lot of space in the refrigerator and I won't have to worry about non-complimentary flavors.

If I put a little extra salt in my buttercream, will that help cut down on the sweetness? I'd like to get the butter cream as light as possible. A lot of people in my family (including me!) don't really like icing.

Well, which buttercream recipe do you use? Also, if it already has salt in it, I wouldn't add extra. If it doesn't have salt in it and you are adding it and you use the recipe that calls for water, take some of that water and heat it up and dissolve the salt in it, let it cool, then add. Or use popcorn salt. For some reason, salt added for some folks makes the icing gritty. It likely has something to do with the type of water in their locality.
I use a recipe similar to Dawn's with butter, shortening, vanilla, cream and whole milk. I use salted butter in it and this does cut the sweet.
I don't use any milk in my cream cheese icing, I find it runny enough without the milk. I am wondering if this is also why it holds up so well at room temperature - this and the fact I use salted butter.
I will go and copy it and post it here.
Hugs Squirrelly Cakes

Cream Cheese Icing

1/3 cup softened butter
1, 8 ounce package of regular cream cheese, not the light kind
2 tsp. vanilla extract
4 cups of icing sugar
Whip butter. Add cream cheese and whip until well blended. Add vanilla and icing sugar and whip until well mixed. Remember to place a buttercream bead around the outside rim of the cake so cream cheese filling won't seep through the sides.

I've been using Dawn's BC recipe. I can't remember if I use salted or unsalted butter. I'll have to check on that.

Thanks for the cream sheese recipe. That looks pretty close to what I remember from the one I have in my recipe box, but that's all the way out in my kitchen and I'm feeling lazy right now...

Haha, I can relate! The recipe for cream cheese icing on the Wilton site has milk added and personally I cannot see why, it is plenty runny enough without it.
Try the buttercream with the salted butter, it will make it less sweet if you normally use sweet (unsalted) butter.
Hugs Squirrelly Cakes

squirrelly cakes:0) what is icing sugar?

gracie

Icing sugar is just powdered sugar.

Jess