crap need a recipe of coloured butter cream icing???

[allthreerolledintoone]

just made some with icing sugar,butter and milk but its gone a bit lumpy or at least the butter has? And is it better to use an recipe with an egg or no? its for a topping making a train cake

Basic buttercream is just twice as much icing sugar to butter/marg. You don't need an egg, and you would only use a little milk to loosen it up if you needed it softer.
Was the butter at room temperature? If you used it straight from the fridge it can be difficult to get it smooth. Let it come up to room temp and then beat it really well until all the lumps are gone.

Ah thankyou you were right think the butter was too cold