Certified GKH Gardening Expert
Many cultivars will have a tinge of color to the flowers. Many will be white as well. Just be sure that you are feeding it correctly, as using any fertilizers containing nitrates (Like MiracleGro) will be a death sentence to the plant.
Ammonium sulfate will be what blueberries will want, rather than ammonium nitrate. Look for this, or just use a fertilizer that is already blended for blueberries. Here is an article that will help:
Here is a collection of articles that will offer much more information for the care of blueberries: