In Halloween (2007), Dr. Samuel Loomis took an observation job over Michael Myers in some facility and he started taping his behavior also in black & white. Why would he record in black & white for his observations?
Most "observational" cameras to this day are B&W. How often do you see store security footage that's in color? B&W cameras were, and are still, less expensive than their color counterparts.
Don't forget; the original movie was released in 1978. Based on that, we can assume young Michael was under observation in the late 50's/early 60's.
There's a little bit of info on surveillance cameras here. The highlights are:
- Color cameras usually have lower resolution than black-and-white cameras.
- Currently, the cost of a color camera as compared to an equivalent black-and-white camera is anywhere from 30 percent to 70 percent greater.
Based on the timeframe of late 50's/early 60's, the disparity in price was probably much greater.