Most people think of indigo as purple, but technically it's a deep dark blue (it was the original dye color of denim blue jeans). I almost got it to my satisfaction here, but I wanted the silhouette of the plant to show through, so I lightened it up a bit.
Thank you Annie, Katrina, Diana, Kathryn, Helen, Katy, Marilyn, Gloria, Carole, Wendy, and Kathy!
@salza Thank you Sally!