Greg,
I have rechecked my sources on the 12th New Jersey. Major John T. Hill, commanding, reports the capture of two enemy colors. Hill does not specifically identify who took those two colors, but he does cite the meritorious conduct of Color Sergeants Charles E. Cheeseman and William H. Griffin. In postwar accounts by Lieutenant Charles E. Troutman, Troutman states that Color Sergeant Cheeseman went forward nearly to the Emmitsburg road and trotted back to the lines with one enemy flag. Cheeseman was afterwards killed in the Wilderness battle. If we are to believe George W. Spring, Color Corporal Putnam captured the other flag, and placed it into the hands of Major Hill. We might speculate that, in the heat of the moment, Major Hill confused Putnam with Griffin, and that is why he does not mention Putnam in his report. The other possibility is that Spring is mistaken, and it was Griffin and not Putnam who retrieved the second set of colors. In any case, to address your last question, no one (that I can find) further describes the two captured enemy colors, other than Spring's comment that one was from an Alabama regiment, which has not been substantiated.