I am wanting to create an array that has shuffled numbers in 6 different fields. I know how to choose a random number, but I don't know how to use that number only once.

This is what I am trying to achieve.

R = 4

O = 1

Y = 3

G = 2

B = 6

V = 5

R = 1

O = 5

Y = 4

G = 6

B = 2

V = 3