I try to add vertex paint ability with separated channels to exporter:
the Vcol channels are stored one of colors:
R - store red
G - store green
B - store blue
A - alpha
and when model going to export this channels are joined into one final color.
But before this action, this abbility just gives you very handy to tweak each channel in personal manner.
And thing is - what I have a problem with this. I have strange bug with it.
look at this original channels: