if you cut a few when they are in prime color and hang them upside down, they make lovely dried arrangements.

It looks as though your hydrangea may be changing flower colour from its original blue to pink. Flower colour changes according to the acidity or alkalinity (pH) of the soil. Add lime to soil to encourage pinkness and aluminium sulphate to promote blue.
They grow best in soil improved with good compost/organic matter and in a position that gets morning sun and protection from sun at hottest part of the day. They are good in pots because you can move them around to the best position (ie. not all day sun). Prune once flowering is over, although it's usually done mid winter. Cut back only the stems that have produced flowers, un-flowered shoots will produce next season’s flowers. Needs to be kept well watered while the flowers are forming and fertilised regularly throughout the growing season.

In Autumn, my blue ones change to a lovely rusty mottled colour. When theflowers dry out, and the leaves drop off or dry out, prune back to just above the leaf pairs, as low as you want. if plant is young, just go back to the first pair nearest the flower. :)

Es realmente así.
La acidez o alcalinidad del suelo son los responsables de la coloración de la flor.
El sulfato de aluminio es perfecto para lograr un Ph mas ácido en el suelo y así tener las flores mas azuladas
Hay que aplicarlo en la tierra , alrededor de la planta ,pero sin tocar el tronco. Durante toda la primavera , una vez a la semana.
La poda invernal se hace mas larga cuando la planta esta en un lugar sombrío. Y un poco mas corta si su ubicación es mas soleada.

If you want bluer flowers, add acid to the soil; the more alkaline the soil, the pinker the flowers.