I can't recall exactly what my results were but I think not. If it works at all you'd need to calculate a color value that included the alpha instead of using dbRGB.
#define dbRGBA(r,g,b,a) (a<<24r<<16|g<<8|b)
I generally prefer to specify the alpha value last because my sensibilities say it doesn't contribute as strong as the primaries to the total color.
dbInk (dbRGBA(255, 0, 0, 128), dbRGB(0,0,0);
No guarantee that it will work. I've taken to directly manipulating the alpha value of images, if necessary, down to the alpha value.
Lilith, Night Butterfly
I'm not a programmer but I play one in the office