I have flown primarily ILS approaches with the G-500 so I decided to try a few GPS ones for practice. In particular, I decided to fly to Clermont County (I69) using the GPS RWY 4 approach. While inbound to NOCFU the IAF, everything is fine. I mean, I am following the magenta line with NAV selected on the autopilot and the GPS switch active on my panel. What I am confused on is when I get to NOCFU, a narrower white line goes to JUPGO, then turns 90 degrees to a heading of 40 deg to head toward the airport and runway. I realize this isn't a localizer, but shouldn't the segment from NOCFU to JUPGO and JUPGO to the airport turn magenta like the rest of the GPS segments? Upon getting to NOCFU, the remaining segments remain white as if the AP is no longer in command to follow the remaining segments. In other words, do GPS approaches end at the IAF as far as autopilot guidance goes, so that one must just manually fly the "white segments" after that?? Thanks. Tom

OOPS. Solved my own problem, and also learned a lesson. Don't forget to activate after loading the approach. :)