According to the above link, the following cultivars are available. I can't find the Amaretto in the database, so I assume the others may not be there either?
The 2018 Summer Spice Hardy Hibiscus collection will offer the following cultivars:
– Amaretto, coral-salmon.
– Ambrosia, fuchsia with white eye.
– Bleu Brulee, sky blue.
– Brandy Bleu, blue, Cordon Bleu, blue.
– Crème de la Crème, white with serrated petal edges.
– Crepe Suzette, bright pink.
– Grape Sorbet, purple, and Plum Flambe, light plum.