I have never seen IR codes for Sony discrete picture mode selection. Pretty sure they don't exist.

Now if you want to control the TV with RS232 (Harmony can't do that), there are serial commands that you can send to activate picture modes.
[Link: pro-bravia.sony.net]

Not sure if you can do it with IP control or not. That webpage I linked to has information about that as well, but I didn't see at 1st glance where you could select specific picture modes with IP.