Q.Why are my lilac blooms so pale and light in color this year?
Last year my lilacs were a nice lavender color and this year they are so pale they are almost white. Is there something they are lacking nutritionally? The bush and blooms themselves appear healthy, just not nearly as colorful as they were last year.
Your plant was probably grown on a white lilac rootstock, the graft may have died which would revert it back to white. In my research it was also suggested that lilacs allowed to attain large dimensions might exhibit smaller flower sizes and a lessening of color intensity. So, it is recommended to prune your lilac on a regular basis to keep it healthy and looking its best. Here is an article that will assist you with pruning:
https://www.gardeningknowhow.com/ornamental/shrubs/lilac/pruning-lilac-bushes-when-to-trim-lilac-bushes.htm
A boost of fertilizer would also facilitate better blooms. For more information on fertilizing lilacs, please visit the following link:
https://www.gardeningknowhow.com/ornamental/shrubs/lilac/lilac-plant-fertilizer.htm
For more information on growing lilacs, please visit the following link:
https://www.gardeningknowhow.com/ornamental/shrubs/lilac/lilac-care-growing-and-planting-lilac-bush-plants.htm