Gradual change is now a very popular technique, gradient style both elegant and elegant, but also lively and pleasant. You can usually operate with a sponge and a gradient halo pen.
Tips：Two-color or multi-color gradient of the same reason, but pay attention to the first to do a dark gradient, and then on the light-colored, follow-up to deepen the gradient color, the same need to repeat the color to do the alternating gradient.
Each color must be coated only a thin layer. Note that when the pen a few strokes each brush will clean the pen color, otherwise the color is difficult to gradually shallow.