Single-flowered is the natural state of the hollyhock and for those that prefer this classic form there are plenty of cultivars from which to choose. "Nigra" is a dark maroon variety with an almost black center. Alcea rugosa is a separate species with yellow flowers, also called Russian hollyhock. The "Watchman Strain" has dark red flowers.
Modern breeding has introduced double-flowered cultivars to the garden scene. These puffball-like flowers are not as good for butterfly gardening but are still a pretty addition to any garden. "Charter's Double" has ball-shaped flowers in red, pink, white or yellow. "Peaches 'n' Dreams" has pink flowers with yellow centers.
If you can't decide on just the right color for your garden, a multi-colored cultivar may be for you. These mixes come in double or single-flowered varieties. "Country Garden Mix" comes in single flowers of pink, white and yellow. The "Old Barnyard Mix" is a single-flowered variety that reseeds every year. "Powderpuffs Mixed" has large double flowers in white, pink, scarlet and salmon.
Perhaps you like hollyhocks but have a small space in mind for them. Dwarf varieties have all the charm and half the height of the standard types. "Marjorette" has double lacy flowers in a variety of colors that only grow about 2 feet tall. "Pinafore Mixed" has single and semi-double flowers in various colors at 3 to 3 1/2 feet.