When you create a chart, Excel uses the default settings for the chart design. You can change the overall appearance of the chart by changing the chart style or by changing the theme. You can also modify the appearance of individual parts of the chart.
Change the Chart Style
Click the chart to select it
On the Chart Tools Design tab, click the style you want for the chart.
Change the Theme
On the Page Layout tab, with the chart visible, click the Themes button, and point to the different themes to see how the appearance of the chart changes with each theme.
Click the theme you want for your chart.
Format an Element
On the Chart Tools Format tab, select the chart element you want to format.
Select the style you want to apply to that element.
Click the appropriate button to modify the formatting applied by the style.
If the selection contains text that you want to format using WordArt, click the WordArt style you like. Click the appropriate button to modify the formatting.
Use the Size tools to adjust the dimensions of the selected element.
Click the Format Selection button, and, in the Format dialog box, click the various categories to make changes to the formatting of the element.
Click Close when you’ve finished.
Tip
To format text without using WordArt, use the font and alignment tools on the Home tab.
Tip
You can select an element for formatting by clicking that element in the chart. You can also resize an element by selecting it and dragging its Sizing handles.