My back yard always had beautiful hydrangeas growing up. It’s one of the few plants I actually know the name of! The colors ranged from pink to purple, and all variations in between.
Then in 1996, in the shuttle from the SEA-TAC airport to my first calligraphy conference outside of Seattle, the bus passed a hydrangea with the most stunning blue petals.
Blue! Deep, vibrant blue!
There was a collective “Ooh!” from everyone looking out the windows, and someone (a gardener, obviously) shared that the colors are totally dependent on the soil, not the plant itself. Something about the acidity, if I remember correctly.
This strikes me as rather metaphoric. Our environments play a large part in shaping us as humans, too.
If you want vibrant petals, then, find the right kind of soil.