They form a symetrical pattern around the first two green pairs. 66 and Other White Numbers 66 is the first white number. It is the last number of a different colour to all lower numbers. Like all white numbers, it has factors of all other colours. Each of its factors are the first number of its colour.
White numbers are quite rare, but gruadually become less rare for larger numbers.
A white number must have at least three prime factors. It has, including both itself and 1, an equal number of factors of each colour. Any sequence of a 3-colour cycle, has a maximum of three odd numbers and so is limited to seven numbers. It also may only have two numbers divisible by 3. These eight consecutive numbers are of all eight colours .