Blue hydrangea turned white

[LuvOrlando]

My beautiful 2 year old blue hydrangea plant bloomed very late & turned white. I gave it hydrangea food a few times over the winter but it didn't work because the food was supposed to keep them blew and now they are white. Does anyone have experience with this? Should I feed it the hydrangea food once a month starting now for blue blooms next year or start over the winter?

I'm in N.E. Pa & our soil here is awful orange clay, if that helps. Also, the flowers are planted on the east side of the house with the morning sun.