Drag the column that will serve as your axis values to the Axis box. These values will serve as the fixed axis of your graph.
Choose which column will serve as the values that determine the sizes of the bars in your bar graph. Place this column in the values box. You can also choose to have a simple Row Count in the values box. You can also apply aggregations directly in the values box.
Place the column with the categories you would like to divide your data into in the Color box. This will split your bars into the number of categories represented in the column.
Click on the color palette to update which colors are displayed on your graph.