So, you got a smart strip, hacked the wall plug off of it, an you were greeted by 3 wires: black, white, and red? That's not what I would have expected...
I'm guessing the red wire is earth ground. This is totally, 100% not standard, but I've started seeing it on some random chinese stuff (somebody recently posted a picture of a monitor on here with a red wire clearly hooked up to the frame as the earth ground).
The earth ground should always been connected straight through. Got a meter? Check for continuity from the red wire to the "3rd prong" on the outlets on your strip to verify.
If indeed red is ground (wtf), then black is probably hot (P - the manufacturer was probably thinking "phase"), white is neutral (standard color in the US), and red is, well, ground.
BTW, household AC doesn't have "positive" and "negative". It has "hot" and "neutral".