Diverging palettes from ColorBrewer https://colorbrewer2.org. Diverging palettes are used to indicate distance from a critical point. These color schemes work well when your data has some mid-point.For example, temperature data could be a shade of blue below zero, a red color is for the values above zero and temperature around zero would have a neutral color.

'宣言
 
Public Class DivergingPalettes 

public class DivergingPalettes