Color Color Color (American English), or colour (Commonwealth English), is the characteristic of human visual perception described through color "categories", with names such as red, orange, yellow, green, blue, or purple. This perception of color derives from the stimulation of cone cells in the human eye by electromagnetic radiation in the visible spectrum. Color categories and physical specifications of color are associated with objects through the wavelength of the light that is reflected from them. This reflection is governed by the object's physical properties such as light absorption, emission spectra, etc. By defining a color space, colors can be identified numerically
Gardner color scale Gardner color scale Gardner Color Scale is a one-dimensional scale to measure the shade of the color yellow. Colors of transparent liquids have been studied visually since the early 19th century. Changes in color can indicate contamination or impurities in the raw materials, process variations, or degradation of products over time. One dimensional scales for yellowness were created, e.g., Gardner Color Scale. The yellowness of the transparent liquid is determined by pouring the sample into a tube and comparing it to a pre determined and known standard. The standard that the sample falls closest to then becomes the value for