I have 3 colecovisions which all have some sort of issue. I decided I'd sacrifice the worst looking one and try to do a composite AV mod (as well as power switch cleaning). I grabbed 5-11 under's instructions and went to Radio Shack.
Grabbed the potentiometer and transistor no problem, but didn't know which resistor to get. They come in various wattages and I didn't know which watt I should get.
1/4 Watt (or anything higher, such as 1/2 or 1 Watt, etc.) will be good.
Also, if you need to substitute parts, there's equations online for that (to double the resistance value, put two the same in series; to halve the resistance value, put two the same in parallel).