Colors Look Paler When Dry
Watercolor paint when wet can look very dark and vibrant and when it dries back the intensity of the color can fade back up to 50%.
If you want a painting with deep, brilliant colors you may need to paint them much darker than you anticipated.
Shown here is a sample of the same swash of colors. Using the same puddle of paint colors, the painting on the left is dry and on the one on the right is wet. Notice how much more vibrant the wet colors appear.
Something to think about when wanting to paint bright, bold color.