No. That piece of vegetation looks green to me. Just keep and eye on the nodes, and when the pistils appear you WILL know. The are unmistakeable. They are white. Don't ever take clones/cuttings after you have switched to 12/12 to flower, if you do, your clone/cutting has to revert back to the veg stage and flipping the switch like that could shock it into sex-reversal...after you veg the clone and switch it back to 12/12 to flower, it could reappear as a male. Don't ever trim the plant for the sake of trimming it. The large fan leaves are needed for breaking down sugars and other metabolic functions. It is common for the older, lower leaves of the plant to turn yellow at one point. They are just old and/or are too low on the plant for the light to reach sufficiently; they will fall off by themselves. (I saw earlier in the post you mentioned trimming. Not sure if you meant trimming or cloning). Anyway, hope this helps.