Ice

That is ice falling from an airplace when it puts the deicer boots on.
These boots inflate, breaking the ice on the leading edge of the wings in small pieces and then they fall to earth.

The color can come from the anti ice fluids used.
No big deal.

Poser 1, 2, 3, 4, 5, 7, P8 and PPro2010, P9 and PP2012, P10 and PP2014 Game Dev
"Do not drive faster then your angel can fly"!