It looks like you haven't added a measure to the chart. To do this expand the Data section and then put the measure in (image attached). You can then go into the "Appearance" section and go to "Colors and legend" (image attached). In this section you can adjust the colors as needed. The easiest way to get different colors based on sales is to use the "By measure" drop down. This will automatically color the dots based on the value of the measure.
Please mark my response as correct or helpful is appropriate so other members can find answers to their questions.