Don, when I lived in Utah I planted Heavenly Blue one year, they produced seed generously (luckily they were in an enclosed planter with concrete around it) My kids had fun collecting seeds, and the seedlings that grew the next year produced dark blue/purple flowers with pink throats, much like the Grandpa Ott's. Every year after that I had the same dark color, but I liked them so I never planted any others. Guess the Heavenly Blue color trait is a recessive, and the dark blue is the dominant trait.
Just suggesting you could collect some seeds from the ones you grow this year, before pulling up the vines in fall, and you'd probably get other colors next year from those seeds. A surprise is always fun and free seeds, too.
