Actually I take that back, I did, a little. With negative painting. That is, instead of painting the sprays of water directly I painted everything around them and left the paper white where the sprays went. After everything dried I used a wee bit of white gouache* on top for extra oomph. However, I didn't have the patience to paint around every single itty-bitty white flower in the planter. So first I painted the foliage and let it dry. Then I laid in the flowers with gouache right on top. I even used gouache to lighten up some of the foliage in front. Hey, Homer and Sargent did this all the time. So I guess it's all right!
*(Gouache is an opaque water-based paint, so it can be used to paint light colors over dark. Unlike watercolor, which is transparent.)