Hydrangea gradient circle

I don’t know if this is normal. Where i grew up, in the south east of England, on the chalky downs, you only ever saw Blue Hydrangea - we knew it as the litmus plant. 

…But where i live now, you get hydrangea is all colours these were all picked on a short 5-10 minute walk to and from my local supermarket.
Anyway, was playing with the heads when i got in and figured they’d make a pretty neat clock.