I would like to use a cinnamon buttercream for my daughter's birthday cake but was wondering if you will be able to see cinnamon flecks in it. I wanted to dye the buttercream pastel colors (possibly blue, orange and/or yellow.

I would say you can definitely see the cinnamon in the icing...I don't know if you've eaten cinnamon ice cream, it looks just like that. Perhaps you'd be better off using a cinnamon oil rather than actual cinnamon of you don't want the cinnamon to be visible?

That makes sense (and this may be a silly question) but is cinammon oil truely cinnamon flavored or is is like cinnamon Jolly Ranchers or Red Hotsof hot. I don't want an artificial flavor. KWIM?

I had the same question recently and found that any cinnamon oil I tried had the "candy" cinnamon flavor. I wound up using really really finely ground cinnamon, but you could still see it. So, I gave up the fight and sprinkled more on the top. Mine was just for banana-nut cupcakes, though, so I didn't have the decorative issues. Was pretty yummy, though.........

Just so you can see, this cake here was iced with the cinnamon buttercream recipe that is in the recipe section here. Can definitely see the cinnamon.
http://cakecentral.com/modules.php?name=gallery&file=displayimage&pid=25131