Just as said, try to smell and taste it, It's most probably fine... This with the "max 3-4" month, is highly exagerated. If you absolutelly cannot take your nic changing color, then ok, but that's it. Yes, the nic changes color, but as known, it takes very very little actual oxidation to make colors, even darker ones. I know it maybe looks gross, but that's it. After very much oxidation, it can take a nice tobacco flavor onto itself, and possible, add some pepperness in the nose during exhale, and a little on the tongue if using higher nic. Sometimes of course, the nicbase can get bad tasting also, but dark nic isn't = bad nic!