Are those 6 shells 12 gauge or 20?
20 gauge came in clear (supposedly, but like the Yeti, I have never seen one) yellow and and then green, I believe. The only color 12 gauge came in was red, except for some extremely rare pre-production blue 12 gauge, which I understand was a first run of shells before Wanda changed them to red. One collector does have a loaded amber 12 gauge. If they are green 12 gauge, which I kind doubt, I'd hang on to them and do a little research. There are pictures of some 16 ga. flat boxes which show they were supposed to be amber in color, which is probably why Wanda changed the 20 gauge to green. Wanda only produced 12 and 20 before they closed the doors in 1971.