After exhaustive research at a top secret testing ground, scientists can now categorically state that yellow is NOT the fastest colour. A spokesperson for the MoSWoPM (Ministry of Spurious Waste of Public Money) said that even though speed blocks do seem to improve performance somewhat, they did find one other colour combination that was significantly faster. When asked what that combination was, however, he wouldn't be drawn and said that it was not in the public interest to release that information at this time. We gather that black engines and frames are involved...