I understand that the blue spectrum is emitted when Hoechst 33342 binds to nuclear DNA. But what exactly is the red spectrum telling us?

I read that the red spectrum can be indicative of apoptosis, cellular complexity, or a proxy for cytoplasmic content.

What exactly is the red spectrum indicative of in terms of the cellular context?

edit**

Sorry for not getting back to this question sooner. I found the answer in this paper: http://www.sciencedirect.com/science/article/pii/0022175995002146#

Apparently condensed chromatin during apoptosis causes hoechst to shift to a red spectrum.