5:7.
To figure this, you just need to read it like the probability of getting a red is 2/7, and therefore any other color on the spinner must be NOT red. You consider the complement, which here would be:
1 - P(landing on red) = 1 - 2/7 = 5/7
In general, the complement of a single event is 1 minus the probability of that event occuring.
