Grey smoke instead of black??

[Concussiveforce]

So I was running around today and noticed that my exhaust was a grey color instead of black like usual. My 6.4 is running with an S&B intake, AFE machforce downpipe back exhaust, and an Edge race evo on the 90HP tune.
Noramlly it would be black on turbo spool up and that was all I would see for smoke. But with the grey, it is on turbo spool and if I step on it at around 70KPH it puts out some grey as well. What could cause this??
I set my chip back to 50HP to tow this weekend, could the towing have had anything to do with it?? Any help would be appreciated.