Answer: It is common for saved seed to produce a plant that is not the same as the parent, especially if the parent was a hybrid. In many cases the color, size, or habit of the new plant will resemble the species more than the parent plant. It sounds like this is what has happened here with the color. If you are careful to only allow the pink ones to seed down, and always pull the purple ones out right away, you might be able to develop a strain of reliably pink lupines over a long period of time, but there is no guarantee.
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