Thanks Nate.
I can't set a fill color to an entire group in Corona so I have to do it to each piece. I could get each piece and set its fill color, but that would be in vain if Spine sets it back.
Spine at least sets the fill color during setToSetUpPose but I'm not sure where the color comes from.
self:setColor(data.r, data.g, data.b, data.a)