Processing Download: https://processing.org/download/

This is your "Hello World" for Arduino + Processing with the OSM

1) Upload RGB_X_Arduino.ino to the OSM with the Arduino IDE

2) Close the Arduino IDE

3) Open RGB_X_Processing.pde with Processing

4) Change the line #15 on "RGB_X_Processing.pde" from  

port = new Serial(this, "COM4", 9600); // Change "COM4" to your COM# of your programmer.

5) NOTE: I don't have my mac here, COM# must be changed to a different format on Mac... please google it... I have no access to google now.