Is there a way to get light blue hydrangea flowers to turn a deeper/darker shade of blue?

Question

I know that changing the acidity of soil allows you to turn hydrangea flowers from pink to purple to blue. However, I notice that some shrubs in my neighborhood have light blue flowers (such as my hydrangea), while others have a deeper, darker shade of blue. I see the same within pink and purple varieties—variations in color saturation as opposed to the color itself. Is there a way to control this or encourage deeper colored flowers? Or does it depend on the plant variety?

Answer 1

This Extension fact sheet says adding aluminum sulfate to the soil will make the blues darker.

https://easttexasgardening.tamu.edu/2014/07/16/hydrangeas-6/

https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/change-hydrangea-color.htm