That is correct, Vicky, The pink cousins of Annabelle will not turn blue; the shade of pink may be slightly diffirent in acidic/alkaline soils but not that much different. It will not affect the bloom color of paniculatas either.

It does help prevent iron chlorosis on the leaves of all those hydrangeas. You need it if the soil in your garden or potted plants is alkaline. And if you are not sure, you can always stop by your local nurseries and get a soil pH kit. If your soil is already acidic, you do not need to amend the soil with a/s.

PS - you will notice that you need to regularly add this every year forever in alkaline soils as the soil tends to return back to its alkaline state. I make a habit to amend in Spring. And in some years, when I notice iron chlorosis in the late summer/early Fall months, I add some more again. You can do the same: add some in Spring and then wait to see if you notice iron chlorosis again. Or use the soil pH kit to test the soil every 2 months or so.