I could be red, blue, green, yellow, brown, white, black, purple, or pink
I look just like you and the rest of your crew.
You better figure me out before you run out of air.
Thide in the vents so you don't know I'm here.
Can you figure me out, or will you vote off a friend.

I believe the rest should be "I'll start to turn your friends against you!"

Step-by-step explanation:

(n^3 - n)

= n(n-1)(n+1)

since it is divisible by 3 and 2 ,because it is a multiple 3 consecutive number

if, n-1 is odd then n+1 is also odd, then it is a multiple of 9

but if, n-1 is even then n+1 is also even, then it is a multiple of 4

so, largest multiple = max(9*2, 4*3) = max(18, 12) = 18