"The green light’s technical meaning is that he or she has completed all of the responsibilities of a jump pilot" - not always, not everywhere, meaning of lights installed in a plane (by a DZ) are not set in stone. Check with the pilot and or staff (and/or locals) for procedures. Also, keep in mind that you starting a knitting club in the door or whatever can f* up the spot (and safe return to the dz) for the rest (or last) of the load. If the local policy is green = go, check for traffic (!always important!) and GO!
How to Spot In The Manner of a Boss
in General