Use color and gradient swatches
While the Color Picker displays only 16 color swatches at a time, Microsoft Expression Design includes many more swatches that you can use. You can also save your own custom color and gradient swatches and use them later.
To display more swatches
In the Properties panel, in the Appearance category, next to the Color Picker, click the More Swatches button .
In the More Swatches gallery, select a color from the Favorites, Most Recent, or Categories sections of the gallery.
Several sets of swatches appear in the Categories section, and you may have to scroll down to view them. You can also click the collapse or expand triangles next to the category names to hide or view a set in this section.
To add or remove custom color and gradient swatches, see Add and remove custom color swatches.