Harvesting cleome -- open pollinated?

Is Cleome what is called an open pollinated flower. I purchased cleome of three colours, pink, white and violet. I would like to have new plants next year of the cultivar, Violet Queen and wonder if I save this seed will it come true to that parent. I was not overly impressed with the pink nor white. I know Cleome self-seeds, but I have a particular spot where I would like the violet one.

 

Bag the seed if you want it in a specific location; my Cleome all comes true from the mother plant, but it broadcasts like nobody's business.