A color is the property possessed by an object of producing different sensations on the eye as a result of the way it reflects or emits light.
In other terms a color is a wavelength such as sounds, microwaves or even Gamma rays that is only understood by eyes.
Range of wavelength from radio waves to Gamma rays (in frequency or inversion number per a time range). source
According to above image,
*Spiritual simply means that because color don't have an official sensation or definition of what it does on human body and mind, it's just a ~precise definition of the average color sensation definition by people's mind.
Red: (Primary color) Passion, love, energy, power, strength, heat
Orange: (Secondary color) Energy, change, courage, friendliness, success
Yellow: (Primary color) Happiness, bright, energy, creativity, intellect
Green: (Secondary color) Stability, fertility, freshness, healing, nature
Blue: (Primary color) Security, trust, intelligence
Indigo/violet: (Secondary color) Harmony, creativity, inspiration
And you, what feeling do you have about colors ?
Color Addition: when colors of light combine: more wavelengths of light present
Color Subtraction when mix two pigments: more colors of light are absorbed (or subtracted)
An excellent article is available at http://w3.shorecrest.org/~Lisa_Peck/Physics/syllabus/soundlight/ch28color/ch28color_images/ch28_images.html to know more about color's physics properties.
