Great book on watercolors. She uses the white of the paper to stay bright as we would use our fine silver. Adding warm colors and light to make the information come forward, adding shadows and cool colors to create distance.
Try the exercise she has, it helps you understand more about layering colors to achieve bright colors. Afterwards practice layering in enamels by making test plates and see the results. Enamels have to layer in a different order.
Water colors can layer yellows first then reds and pinks followed by the darker colors, like blues and greens. In enameling our warm color burn out so we need to leave them toward the end. So you just have to apply this in reverse. I start with the darkest colors first. Then medium and light colors. As I layer and fire I leave out the darkest color and continue with the medium and light colors. And finally have my lightest color last.
So enamelist add fluxes to the last layers to fill the cell. I have had this get cloudy on me so I continue with color in the same family but very light. The warm colors you can start adding about half way through the project using flux for several layers first then jumping into the yellows, oranges and reds.