Siben,
There are actually three, not two, types of ammunition visible.
Green body, white band, black tip
Green body, black band, red tip
Green body, white band, red tip
The color coding of the Red tipped is for HEIT-SD (High-Explosive Incendiary Tracer, Self-Destruct)
The black band/red tip is for HEI/SD (DT) (High-Explosive Incendiary, Self Destruct - Dark Tracer)
The odd one is the white band, black tip one. I cannot figure out what that is, since it is not listed on official documents I can find. AFAIK black tips are for Tungsten core, but not sure. I will research.