It's important to realize the association of the colors red and blue when wiring devices for NMEA-2000 networks. These colors were only used by Lowrance. Years ago Lowrance's plugs used to be color coordinated. What Lowrance calls red are now actually a black plug. These plugs are pretty much the standard for NMEA-2000 networks. What Lowrance calls blue is their own style of connector used only by them on earlier NMEA-2000 GPS networks.