After a lot of searching on the internet I was unable to find a standard set of colours for radio control PCB headers (e.g. Tx & Rx pins on a flight controler). The only standard ones I could find are, red for + voltage (usually 5v) and black for - / ground. Using white for a PWM or serial Rx pin also seems common but not universal.
With this in mind and in order to help myself when wiring up my RC electronics I have decided to use the following colours. Please note that they are in no way a specified standard. They are just colours that are convenient to me.
|+ voltage 4.5v or 5v||Red|
|- / Gnd||Black|
|Serial receiver / UART Tx||White|
|Serail receiver / UART Rx||Blue|
|+ voltage other than 4.5v or 5v||Yellow|
I found that when soldering header pins to PCBs it was easier to solder them on as a single strip (ignore the colour of the strip). Then remove the plastic coloured part and replace it with the correct colours for the individual pins.