If you have a really dark color on the background of your pages, so dark that you cannot see your text to edit it, you can change the color of your Edit screen.
Note: Same as preview will automatically match the color you have setup on your template. Use color is only used if you want to work in a different color other than what is in your template.
Note: This function is not used for actually changing the background color of your page. It is only for working in Edit mode. To change your background color of a page, you need to have your template updated or you can specify a background color in a table.
See also Advanced styles