Track the last 30 spins.
Check which color appeared most. Black or Red.
If for example the black uniques appeared more than red, let's say 10 times, then you will bet waiting a black number repeat.
If the black uniques appeared less than red in 30 spins, for example, only 8 blacks uniques, then you will bet for a unique black number.
After 30 spins you see the black uniques appeared for example only 8 times. So you will bet the 10 black uniques (one chip each black number) and put 10chips on red outside bet.
This way when a red number hit you break even and keep betting waiting for a black number. (Unique or repeat depending of the avarage).