Working with Color - Adobe Illustrator CS6 on Demand - page 265

Select the Color Guide panel.
Click the Edit or Apply Colors button on the Color Guide panel or click the Re-
color Artwork button on the Control panel.
Click the Edit tab.
Select the Recolor Art check box.
Click the Get Colors from Selected Art button to create a color group from the
selected objects, and then enter a name in the field next to the button for the
group.
Click the New Color Group button to save the color group in the list.
To change color groups, select one from the Color Groups list or click the Har-
mony Rules list arrow, and then select a rule.
To edit a color, select a color box, and then drag the sliders and the round markers
(largest marker is the base color) on the color wheel to display the color you want.