To edit the appearance of text, first select (highlight) the text you wish to edit. 
 
Next choose the font from the font-family pull down menu as shown below:


 
Now choose the size font-size pull down menu as shown below:


 
Finally select the text color button to edit the color of the selected text.  Read more about color selection.

Caution: if you want to edit the color of link text, please select the link and use the edit link dialog to change the color.  Read more about link properties.