Why at night, under the mercury or sodium vapor lights in a mall parking lot, do cars seem to be peculiar colors?

Here's what I find  

Explanation:

Sodium vapour produces mostly yellow light.

Mercury vapour produces mostly blue light.

A white car reflects all colours back to our eyes.

A coloured car, say green, absorbs all the other colours and reflects the green.

Under a sodium light, a white or a yellow car will appear yellow. A red car will be nearly black because there is no red light to reflect.

Under a mercury light, a white or a blue car will appear blue. A yellow car will be quite dark, but there will be a yellowish tinge because there is some yellow in the Hg spectrum for it to reflect.  

The picture below shows a red car and a black car under sodium light. Can you tell which is which?

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.