Create a color map that you apply to both transparency and color. In general for colored glass the transparency color is similar to the diffuse scattered color. Also add a bump/displacement map to handle both the lead and the rippling of the glass. You may wish to additionally map translucence. Raytracing will further help realism and lighting setup is important. In terms of reflectivity the glass should be much more reflective at glancing angles than dead on. This can be accomplished by using a blinn shader and lowering the specular rolloff (specular rolloff affects reflectivity for raytracing in addition to specular highlights) You may wish to make the specular color brighter than 1,1,1 when doing this.
Duncan