The first flowers on my hydrangea were beautiful and blue. About two weeks later, however, all my Hydrangea flowers are light green. Pretty, but I prefer blue. Why do they change colors?
Certified GKH Gardening Expert
When hydrangea blossoms turns green, this typically means that it cannot take up the nutrients it needs to produce the colors in the blossom. This can be due to the fact that the blossom is older and fading or just opened, or because the soil is lacking in nutrients. This article will have information on how to get blue or pink blossoms, so add nutrients to the soil for your desired colors and the color should come back: