My latest dry-hopped beer had a brownish-greenish, downright unappetizing sewage-like color. It looked okay during bottling, but I was disgusted at the first pour after 3 weeks in the bottle. So I left the beer on the shelf for another month to rehabilitate - and I find the hop residue has dropped to the bottom of the bottle and I have a fine beer with a lovely reddish-gold color. The bottle trub in these beers is dark so there's no question I had a good amount of hop residue in solution during bottling.
I fermented 3 weeks before dry hopping, the primary phase completed early in week 3 - dry hopped with 2oz pellets during weeks 4 & 5 in the primary then bottled. Temp was 68° weeks 1-4 and 64° week 5.
I think my mistake was around the end of the first week of dry hopping when I swirled the carboy a good bit to try to sink the floating hop scum. I figured the following week would be enough time for the hops to fall out. Maybe I reactivated the yeast and they kept the hops in solution, I don't know. This recipe had a fair amount of Carapils, perhaps the yeast decided to have a second go at fermenting it.
I haven't read about anyone else having this problem, but it makes sense that tossing the equivalent of powdered hops in the fermenter may cause some to stay in solution. Next time I might consider using either leaf hops, and/or a hop sack, and/or a more significant cold crash. Suggestions are welcome.