bottom tier is a 1/2 sheet cake. I put dots of color one at a time on the cake top and blended with my finger to mute to the right color with the white icing I frosted it with. I usually use my spatula to do this, but wanted a rustic look although I did use the offset spatula to blend colors with some warm water last.
On top 1/4 sheet cake I added different tones of blue and added white last to blend in for some highlights in water surface. grass tip around water and sides of cake. figurines added on top per request of customer.