It could be bud rot. But first, Are you using a Humidifier at all that could be putting out calcium into the air ?
How close were the buds to the light ? Could be light bleaching also. I've had some Albino looking buds in the past from Light bleaching. Those buds wont get you high. Trichs are wasted.
Bud rot starts on the inside & works it's way out. If the center of the bud isn't rotted it's probably not bud rot in my opinion.