Hummingbirds learn by trial and error which flowers will provide the greatest amout of nectar. This is surprising, to me, because hummingbirds have the ability to see into the ultra-violet rannge, so I figured this was the explaination for their choice of a partular flower. The ideal colors to attract hummingbirds are red, orange and pink, but others will do a good job as well.
Tubular flowers are known to be a favorite with hummingbirds, because the shape of these flowers make it easy to use their beaks to probe within the flower for the nectar. Usually, tubular flowers are known for holding a large amount of nectar at the base.
Another important consideration when designing your hummingbird garden is that the plants you select should have various bloom times. The goal is to provide the hummingbirds with a natural food source and thus entice the birds to remain around for as long a possible. The hummingbirds will be nesting from March through September so during this time the birds will need a depenable food source. Due to their very agressive and territorial nature, hummingbirds will vigorously defend a food source, so it may help if you have more then one area in your yard that is designed to attract the hummingbirds. This will help to ensure that several hummingbirds can be feeding at the same time.