Getting started with Codebase

I’m trying to follow along with the wiki provided here to understand better how the code is working at a deeper level and write some of my own programs:

http://ardupilot.org/dev/docs/learning-ardupilot-the-example-sketches.html

After doing
cd libraries/AP_GPS/examples/GPS_AUTO_test make px4-clean make px4-v2 make px4-v2-upload
The pixhawk’s main LED stay’s pink. Is this normal?

Also, can someone recommend a good way to see the serial messages of what is being output once I get the sketches working? I can’t figure out how to run the sketches. Do I need to make a serial port to USB cable or should the standard USB port on the side of the PIxhawk work for this? I’m using Mac OS.