"It blooms with 7-9" single flowers with beautiful form. In cooler weather, the colors are soft, pastel blends of yellow, tangerine, and pink. In hot weather, the colors become hot, vivid rings of yellow, red, and fuschia. It's full, branches naturally, sports lush foliage, and is very strong and upright. Tried and True hibiscus, 'Rainbow Sherbet' is an orphan of unknown parentage. Released from HVH in 2007."

**********

The bloom in my photo was on its way out, but still pretty in an "aged" sort of way.
Here is the same plant when it was outside last September: https://pbase.com/britestar/image/173020637