Lilac bush

Question

While my lilac bush produces every year; what would cause the flowers to be almost white this year instead of their usual violet?

Answer 1

Flower color can fade over time and chill hours on your Lilac Tree effect blooming on a plant.
This could very well be due to the Hybridizing of the plant. A tree can began to revert to another part of the hybrid.

Sometimes a tree will send out a branch of two of a different color all together.

https://www.gardeningknowhow.com/ornamental/shrubs/lilac/lilac-care-growing-and-planting-lilac-bush-plants.htm