In my efforts to capture some main sequence stars as a starting project, I recently targetted HD120787. In Deep Sky Planner 7.0, this was given as G3V. I was disappointed and puzzled when, even after several attempts at instrument response correction, it didn't look much like such a beast. I then dug down a bit using Simbad and Vizier with some interesting results... In the simple Simbad search, it also lists this star as of type G3V. However, looking at other catalogues it cites K0. I followed up one of the papers on Simbad (Willmarth et al., Astro. J., 2016) who note that "Takeda et al. (2008) .... determined its effective temperature and gravity, which correspond to a K0 III"
So, attached, is my spectrum alongside relevant Pickles references (there is apparently no G3V a such, so G2V sufficed). I was pleased to see a close match to the K0III !
So moral is - don't believe what the catalogues say! :)