why is shadow matte in the alpha colored?

[caypiranha]

... in mycase often "blueish". Why isn´t it a simply a B/W Gradient?
It doesn´t matter if the matte was generated via the Object properties or Mattematerial.

[kosso_olli]

Because there are programs out there which can handle and interpret these colored alphas correctly. And no, Photoshop is not one of them.