Heathkit SL-5798 Motion Sensor Wiring Diagram
This thing is made for the North American market (note the Heath/Zenith branding, classic zombification of old loved brands which would only be meaningful to US/Canada customers), and those stalk motion sensors are commodity items on a modular fixture.  You can buy similar motion sensors off-the-shelf.  Any component maker who wants a UL listing, or who sells to fixture builders who want a UL listing, will use US standard colors. 

And red/black/white/green are the exactly the textbook standard color set.  Given the branding and commodity nature of these parts, the chance of them being anything else is vanishingly small.  

UL and NEC say Green is safety-ground... and White is neutral. 

Black and red are "hots" but NEC does not specify further.  By convention, black is always-hot, and red is switched-hot. But a component maker could go another way and face only the wrath of their customers.  It probably won't fry the sensor if you reversed them. 

Now, how did this stripped unit come into your possession?  Consider the possibility it's maybe because the sensor is roached.