A close up view of daffodils and tulips
The intense colors are achieved by glazing. Glazing is the painting of layers of colors.
With watercolors you start with the most opaque colors first and add layers of transparent colors. You do this after each layer is dry and you have to add the new color quickly so as to not get the under painting wet and create a muddy color. The colors I added in painting the red tulip there is Alizarin Crimson, Scarlet, Cad Red and Permanent Magenta. I painted this painting to show some students, who taunted me for not painting flowers, that I can paint flowers.