I'm making a three tier teal cake.  I've finally got all the layers smooth in buttercream icing and in the fridge, but they have dried splotchy!  I did make two batches of icing, but I put the exact same number of color drops in each batch and each batch was the exact same size.  I used hot water to help smooth my icing, and that looks like it may be what the problem is.  Is there any quick fixes I can do?  Since this is my first real cake, it took absolutely forever to get the tiers smooth :(

ASince the buttercream is already on the cake Im not sure of your options at this point :( the only thing I'm thinking is maybe when you do your decorations you can cover up some of the spots? Maybe there's a pro here who will have an idea. Good luck

cover it all up with decor or re-ice it--you could try airbrushing it maybe if it's not a real severe difference in coloration but you'll probably have to re-ice and ditch the water right--

Yep it's the hot water.  I don't use hot water to smooth my BC because it splotches my colors and even discolors my IMBC with no coloring added. 

Maybe you could take your scraper and try to shave off the top layer of the icing?  Not sure what kind of BC you use but if it's IMBC or SMBC it should be easy to do.

I agree, it's the hot water.  Why not hot water the whole thing over again and maybe the reapplication of hot water over the lighter spots will darken those areas to match the darker ones.  Place each tier into the freezer for 15 to 20 minutes, then apply the hot knife method - reheating the offset spatula frequently.  I find that if the cake is kept in the refrigerator, all the splotches disappear when it's taken out of the fridge and hits warm room air.

AI would say airbrush it.

AI think I misunderstood...Did you add hot water to the BC when you were mixing or after it was already on the cake?

it's the one that's a technique to get buttercream smooth where you use a wet spatula go over the just iced cake to make it seamless smooth--the water/hot water can leave the icing streaked.