Why did your forsythia bush not turn yellow?

There could be several reasons why your forsythia bush didn't turn yellow. It may not have received enough sunlight, as these plants require full sun to produce vibrant blooms. Additionally, improper pruning or unfavorable weather conditions, such as late frosts or unseasonably cold temperatures, can affect flowering. Lastly, nutrient deficiencies or root stress could also hinder its ability to bloom properly.