Odd even Javascript Function

I am trying to create a function which return either odd or even when certain conditions are met.

For example, if the last 5 spins equal the below:

odd, even, odd, even, odd - returns odd. even, odd, even, odd, even - return even.

There must be at least 5 spins before the function returns either odd or even. It must not return odd or even if the above scenario does not unfold. For example:

odd, odd, even, odd, even - Does not return anything. even, even, odd, even, odd - Does not return anything. odd, odd, odd, odd, odd, - Does not return anything. etc....

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I have been trying for a while now but cannot seem to figure it out. I can't create the random spin or perhaps I should two functions, one to create random odd even then another to act on it.