Several weeks ago a contractor building an addition on my home
installed R-30 insulation in an attic space, right above a ceiling.
The ceiling has now been sheetrocked but I can still see the insulation
in some holes cut for speakers and in the ceiling of an unfinished
untility closet.

The original color of the insulation was bright yelllow.

Above the speaker holes the insulation is now solid black. And in the
ceiling of the utility closet, behind a plastic moisture barrier that
is stapled to the bottom of trusses, the insulation is streaked with
black.

Is this right? Why would the yellow insulation turn black?

mh