Excel formats the plot area a standard gray color. But you can choose another color, use no color at all, or go wild and use pink or purple for the plot area if that's right for your chart. But your chart will have a professional look even if you use plain white (or any other color) when you use fill effects.
In Figure 1 the plot area is white with a gradient fill, which shades the white color from light to dark. The chart also has no border around the plot area, which is an easy way to give a chart some distinction. You'll see how to delete the border in the practice session.
To use a gradient fill, you'd select the plot area, right-click, select the Format Plot Area command on the shortcut menu, select Fill Effects, and then select a color. Do you recall that we said there are two methods of making changes? You can make the same change by clicking Selected Plot Area on the Format menu.
You can also choose other colors for the columns that represent the worksheet values (or data series) on the chart. In Figure 2, new colors represent the number of cases of chocolate biscuits sold by Peacock, Davolio, and Suyama.
A gradient fill was also used for each data series to give the colors some shading and depth. The darkest color represents Peacock, whose sales in February were the highest for the quarter, to draw attention to her achievement. The gradient fills define each column well enough that borders around each column weren't necessary, and could be deleted.
In general, avoid putting two dark colors next to each other. The contrast between light and dark adds extra emphasis to your data and makes it easier to see the differences between the different data series. Greater contrast between colors will also help anyone in your audience who may be color blind to read your charts.