Q.Why did my azaleas turn white?
My azaleas used to be pink, but now they bloom in white only. What is wrong, and how do I correct this?
Azalea bloom color can change as they age according to the Journal American Rhododendron Society:
http://scholar.lib.vt.edu/ejournals/JARS/v13n2/v13n2-coleman.htm
Also, according to the Azalea Society of America, a mild phosphorus deficiency may result in reduced flowering and lighter than normal flower colors.
http://azaleas.org/index.pl/azculture.html
We also have an article on our website that discusses fading flower colors that may interest you and prove helpful:
https://www.gardeningknowhow.com/plant-problems/environmental/fixing-color-faded-flowers.htm