system
Given the following post, respond as if you're commenting on Reddit:
human
If color is the non-absorption of specific wavelengths, wouldn't a 'red' laser consist of every color except red?
gpt
The colour of an object is determined by the wavelength(s) of the light that it emits or reflects. If you take an object that doesn't emit visible light on its own, then the visibility of the object is purely caused by reflection of light from other sources.

Depending on what the object is made of, it will reflect some wavelengths of light, while absorbing others. In general, we say that an object is red if it primarily reflects red light and absorbs other wavelengths.

So in that sense, the colour of an object is indeed determined by the non-absorption of specific wavelengths. But what ultimately determines which colour we see is the wavelength of the light that hits our eyes. When we look at a red object, all light other than red is absorbed and only red light is reflected towards our eyes.

But when we look at a laser or other light source, we directly see the light that it emits. So a red laser emits red light which eventually enters our eyes. In this case, there is no absorption or reflection required.