Google does not have any meaning. It is just the misspelling of word “Googol”, which simply mean ‘equivalent to ten raised to the power of a hundred (10100).’
By using non primary color in the google, it has clearly passed the message that google do not follow any rules.Unlike other, it does not want to use primary color only.
Further, as per wikipedia, it was found that colors are assigned to letters according to whether their positions represent a prime number or don’t.Prime number 1, 2, 3 and 5 are assigned with prime color blue, red, yellow and green where as non prime number 4 and 6 are assigned with non prime color blue and then red.