Skin color is determined by melanin produced by melanocytes. These cells are found in the epidermis.
Your skin color is determined by the amount of melanin inherited from your parents.
Eye color is determined by the amount of melanin in the eye.
Output is not a color. It is the amount of something that is produced by a person, machine, or industry.
The color of the eye is determined by the amount and type of pigments in the iris of the eye.
The color of a beer is determined by the malt. The most common color is a pale amber produced from using pale malts.
i use a keratin based leave in conditioner sometimes and i haven't seen any change in my hair color. If you do a keratin straightening treatment i don't think it should change your hair color either, I've seen before after pics of people with the keratin treatment and it didn't do anything to their hair. It does cause some heat damage and that might change your hair color though...
it is determined by your DNA
The color you perceive is determined by the wavelength (or frequency) of the light.If it was determined by the intensity of the light, then a street light would steadily change coloras you approach it, pass it, and recede from it. That might be quite beautiful, actually.But where I live, it doesn't happen.