Thanks Chuck - I confused 'forms' of a pigment versus another "named"
pigment. Time to haul out TWOI again.

<Actually, not true. Check pg 426-427 in TheWorld Of Irises. The
Xanthophylls are higher order pigments derived from carotenes. Found in
plastids. Eleven of them have been found in iris as well as the four
basic carotenes.

Only the one anthocyanin has been found, delphinidin , in many different
forms. Plus several flavanoids, which are also in cell sap (mainly, as
are manufactured in cell plasma and then transported to cell sap.)>

I like to go back and forth between the theoretical and the practical.
Sometimes, the theoretical provides some understanding of what I'm
seeing and vice versa.

<After having said this, I must point out that fussing over all this is
best left to theorists, as trying to use this in hybridizing doesn't
make much sense, given complexity and in addition having to be
concerned re intensity (amount of these present), plus colour effects
from combinations, plus modification from cell sap ph.. >

So when hydrangea blooms change color in response to pH, that's a
mineral uptake effect, not a cell sap pH change?

<Basically cell sap ph is independent of soil. Ph of soil can effect
plant uptake of chemicals and minerals, so can effect colour of flower,
but not much effect, if any on cell sap ph, which is controlled by plant
genetics.>

White is certainly abundant - maybe this one would do...MATRIX,
CELEBRATION SONG, RENOWN. Keeping my fingers crossed for some rebloom
on this one.

> So you can perhaps use a very nice white for instance, or a pale lavender etc.

Linda Mann east TN USA zone 7