It would be interesting to figure that all out! If you could figure out the factor in the change, you could manage to have multiple colors of your own!

neat thought ... like they do a bit of with hydrangeas..below a PH of 6 the flowers are blue.. above a PH of 7 the flowers are pink or red... between 6-7 they might be pink and blue.. I should test my soil and hers for PH and see if there is any difference...

Great Idea. Never gave that a thought.

Gordon-- that is exactly what I was thinking about! Hydrangeas!