Euro Cyclist Club, rules 7-9

7. Cycling shoes must contain at least 80% white!
The following exceptions apply…
i) Colours combinations such as world cup stripes, or Olympic gold where title has been EARNED.
ii) Shoes which are custom-made for specific riders by companies endorsed by this group. These shoes will be accessible to the particular cyclist only, and shall follow the preceding rules.

8. If white cycling shoes are not available where you reside, white booties with prominent logos shall always be worn. When booties are worn, socks should protrude approximately 7 centimetres above the ankle, and shall always protrude at least 1.5cm from any booties worn.

9. Your bike frame must contain 2-4 colours IN ADDITION TO WHITE. All colours are acceptable as long as they combine tastefully. In addition to this, wheel selection must also match frame and fork.

(From the Facebook group "The Official Rules of the Euro Cyclist.")