Why would a Yellow helicopter mimic an Orange car? You do realise that Yellow is a different colour to Orange. Oh hang on I've got it, you are colour blind so they all look grey to you anyway but that just complicates things even further introducing another colour.
Unfortunately your supposition is incorrect. In fact I have perfect colour perception.
Yellow is used to mimic orange because Ford charge a premium for (Electric) Orange which the RAF obviously cannot afford. Insipid Yellow is the nearest (chromatically speaking) and cheapest alternative.
Edited to say, I called ext 6214 but there was no one there by the name of Samurai, Matt or any combination thereof. You, Sir, are a liar.
Edited again because I'm a numpty that can't remember a four digit number.