Just as an "FYI", I've enhanced the ardupilot-solo v1.5.3 firmware to expose all the features of Solo's motor pod LED controllers (aka OreoLED) over mavlink. With this firmware loaded on the pixhawk, each LED can be fully controlled, including setting any RGB value (color) and "blink" pattern (strobe, sine, etc.). A command line utility, installer, and firmware are available here: GitHub - hugheaves/solo-led-control: Command line utilities to control 3DR Solo LEDs DISCLAIMER: Obviously, this is a customized version of software that controls the flight functions of the 3DR Solo. If you choose to use this firmware, in all likelihood, this will cause your drone to crash, causing horrendous loss of life and billions of dollars in property damage. You have been warned. Here's a quick picture showing Yellow, Green, Blue, and Red.