First post here, and this is an old thread, but I had to respond. As Breakneck said many times, this is not mold. I'm new to indoor growing, but never in my years of outdoor growing did I ever see anything like this; and the culprit seems to be the LED lights. My first indoor grow was Sannie's Kollosus. On at least three of the plants I had these same white calyx's. Not a ton, but in a cluster at the top of the cola and on some of the larger buds.
My current grow is Mandala's Satori, with different nutes, and the same thing is happening again and this time it also involves a few of the small guard leaves on top of the cola...they're half white. Looking at them under a magnifying glass the calyx's are absolutely covered with trichs; I've never seen such trich density. Same on the leaves. I clipped a calyx off the cola and ate it, and it tasted just like hash! It even had that burn on the tongue and roof of my mouth like eating hash gives you. Yep, "Hash Calyx" it is, and it has to be the LED's.