You can set which colors are displayed for which values.  How you do this depends on if you are using a measure or a dimension in the color drop zone.

If your color is based on a categorical variable:

• Right click on each entry in the chart legend

• Select Edit "[Item]"
• Choose a color in the subsequent window

 

If you want to set colors based on defined ranges for a measure you can create a custom color measure

• Create a Custom Color Measure in the Formulate App
  • Open the Formulate App for your model and select formula
  • Create a conditional calculation as shown below to define what colors you want for each range.  You have access to the full library of functions to define this logic

• Drag the the measure created above into the color drop zone.  As you add this dimension to the drop zone make sure to select the custom color option