wxColourDialog with Alpha?

[c.Kleinhuis]

> c> now i am coming right back to a question i asked before, can i use
> c> dc.blit to handle the alpha transparency ?
>
>  Yes, what does it have to do with wxColour and especially wxColourDialog?
>   
wxColour is the base data type for wxBitmap - so  if i set the alpha 
value of a bitmap pixel via wxPen(wxColour(r,g,b,a))

i am just asking on how to do it, i saw the image sample, where png's 
with alpha transparency are loaded in

so, can i uses wxDc::Blit to draw an semi transparent image on to de 
devicecontext?