doc: Clarify that the colors in composite_color* should not include the alpha
Submitted by Debarshi Ray
Some methods like gdk_pixbuf_fill take a guint32 parameter that represents a pixel as a RGBA value, while gdk_pixbuf_composite_color* expects the guint32 color parameters to be a RGB value without the alpha.
It took me a while to realize this. The fact that it particularly says guint32 led me to assume that it is a RGBA value. It might be worth clarifying this a bit.
Version: git master