A chart theme applies formatting to elements in a chart. For example, for a chart title and axis titles, a theme can specify a font, its size, and whether it is bold, italic, or plain. Also, a theme can specify a line thickness and type for a chart border and a background color for the chart. If a developer provides a theme to apply to a chart, you can select a theme name from a list to apply it. To remove an applied theme, select None from the list.