excel vba根据点值更改数据点的条形图颜色

I have a some charts that in which the X Values are text and Y Values are numerical. I want to color each bar Red if the Y value for the bar is less than zero, Green if greater than or equal to zero. Also, if the X value of the bar is "NET CHANGE", I need the bar to be yellow. I followed the directions in a previous StackOverflow thread here: I have a some charts that in which the X Val