I asked my cousin, who lives in the U.K., about the darts that Raleigh used on their paint sceme and he told me it was used only on 1961 to 1962 Raleigh bicycles. No reason why or why it was discontinued.
So @Oilit has me thinking about the beautiful darts pattern. Raleigh Industries was acquired by TI in 1960. A few years later someone who was originally a pencil-pusher at TI gets a questionably earned promotion and decides to ax the darts to go back to an old standard paint scheme that was "the foundation of the company ". Everyone claps and they get a pat on the back because it will also be cheaper and easier to produce. Hmmmmm. Conspiracy theory? Maybe so, maybe no.