On the Format menu, click Color Schemes.
To remove the currently applied color scheme, in the Color Schemes task pane, in the Apply a color scheme list, click None.
Note: Only some of the items on a form template change color automatically when you apply a color scheme. If you have manually applied colors to other items on your form template, such as the backgrounds of controls or table cells, clicking None will not remove the color. Instead, you will need to remove or change the colors manually, by using options in the dialog box that you used to apply them.