4Th Birthday Giant Cupcake Cake

This birthday cake was for my nephew Mason's 4th birthday. He passed away before his first birthday at just 9 months, and each year on his birthday my family and I throw a huge "Un-Birthday Celebration" for all the children in group homes within our city. This year we celebrated at a local park and had carnival/water games and activities. Even though the party was in the morning, in Arizona during the summertime, the heat becomes unbearable by 11 a.m. Therefore, I opted to decorate the cupcake cake with buttercream. I prefer the smooth, candy melt look of cupcake liner portion, but knowing that this event would be outdoors, in the summer, in Arizona, buttercream was a better option.
This cake was accompanied by 500 cupcakes of various flavors for the foster care children to eat.
What a beautiful tribute! Can you tell me how you did the blue sides. Thanks.
I frosted a base coat with an angled spatula and then used the Wilton 21 tip going from bottom to top. Hope this helps!