How to Change Bar Chart Colors in Tableau with the Color Shelf

How do you change the colors of bars in tableau in this example I have a bar chart of total margin by business line and they're all colored blue I can change the color by dragging a measure or Dimension onto the color Shelf let's try adding business line and you'll see that if I put business line on color I have a different color for each business line I can take that off and drag total margin. Onto the Shelf color Shelf this time I get a colored bar so I get a diverging bar from red to Green and as the mouth goes down it turns red and the mouth goes up and turns green you don't have to use the same measure I can put Revenue on the colors and the color the bars can be colored by Revenue even though revenue is not shown in the view and that's how you change the colors of bars and Tableau.