The meaning of graphs can be enhanced with  legends or labels and formatting such as types of graphs, alignment of labels, meaningful colour of columns, background colours and by adding a border.

To add legends (labels) click on Chart tools , then select the Layout tab and click Legend.

To change the type of graph click on Chart tools, then select the Design tab and click
Change Chart Type. 

To change the alignment of the labels, activate the graph by double clicking it.  Click on the Category axis until blocks appear (circled below). 

Click on Format Selection on the Layout tab. Then select Alignment.

Change the degrees in the custom angle bar. In this example it has been changed to -50 degrees.

To change the colour of the columns, activate the graph by double clicking it.  Click on the column whose colour you wish to change. Select the Home tab, then click on the fill colour icon and choose the colour you want.

To change the background colour, activate the graph by double clicking it, then click in the area whose colour you wish to change. 

Then click the Home tab and select a new fill colour

To add a border to the graph, click on the graph ONCE, i.e. do not activate it. Click on Format on the menu bar, then Borders and Shading.