In this worksheet we have a chart with basic formatting.

In either case, start by selecting the chart area.

For example, I can change the font size to 12, and make all text blue.

Note this also affects text that’s not visible.

If I unlock the legend, that text is now blue as well.

you’re free to also make changes to a single element in the chart.

For example, if I grab the chart title, I can change the color to red.

Then use the Font menu to make the text blue again.

The same is true with other elements in the chart.

Now with the chart title, you also have the option of formatting with the mini toolbar.

Click once to select, then double-click to select text and bring up the toolbar.

Curiously, the format task pane does not have font name or font size tweaks.