The leaf looks pretty good, a little dark, but photos can be deceiving. If you're talking about the leaf tips being yellow/brown, I believe you've got a tiny, tiny bit of nute burn going on, but nothing so bad that I'd change much unless it gets worse. If it gets worse or you start getting "clawing", try reducing the Nitrogen a little. Really need to know what your grow media is and what nutes your using, PH, and perhaps EC or PPM of the water. A full picture of the plant would help.