They are called Day Lillies, and the color is called Amber Sunset. One of the easiest to grow and most popular lillies that there is.

"""Like their name Hemerocallis, "beauty for a day", the individual daylily flower lasts only one day. However, a single plant may produce over 50 flowers. This large number of flowers can extend the blooming period of a plant for several weeks. With over 10,000 cultivars available and with periods of bloom available from very early to late in the season, daylilies can be blooming in a garden with the iris in the spring and continue through the fall chrysanthemums.
Daylilies are some of the most tolerant and popular of the garden perennials."""