Step 1: Put on a base coat. This one is Sally Hensen Green with Envy. I love the pastel nature of the shade.Use two coats if you must.
Step 2: Get a sponge with a nail gradation of both the tones. For the darker tone, I used a dab of Models Own True Blue to get a deeper green tone.
Step 3: Finish the tips of your fingernails with a deeper shade of blue. Clean off the additional nail paint from your fingers before you apply the top coat.
And here you are, your graduated greens.