
Color : Modern concept of color was founded in 1774 by Isaac Newton. Newton separated white day light in to a sequence of colored light call spectrum ( VIBGYOR ). According to the committee of colorimetry of the optical society of America.
Color is the sensation which occurs when light enters the eyes. It is orising from the activity of the retina of the eye and its attached nervous mechanisms. This activity is being, in nearly every case in the normal individual a specific response to radiant energy of certain wavelength and intensity.
Color perception depends on three factors. We generally describe color using the three terms hue, sensation or lightness. The hue refers to the actual color sensation (red, yellow, blue), the sensation or chroma (depth of color) to the degree of differentiation from grey (dull or Vivid), and lightness to the amount of light reflected from the object (light or dark). In the munsell color system, these attributes are assigned alphabetic and numrical levels.
There are mainly two types of color Mixing process
- Additive color Mixing
- Subtractive Color Mixing
1. Additive color Mixing : Additive color mixing refers to the mixing of colored lights and the rules below follow from what is observed when the lights are shown together on to white screen, which will reflect almost all of the incident light to the eye. The three primary colored lights are red, green and blue are called primary colors because they can not be produced by mixing together any other two colors. Also a wide range of colors can be produced by mixing these three primaries in different proportions. A mixture of equal proportions of all three primaries produces white.
Red+Green+Blue = White.
If two primary colors are mixed in equal proportions a secondary color is produced, for example :
Red + Blue = Magenta
Red + Green = Yellow
Blue + Green = Cyan
Thus, Magenta, Yellow and Cyan are secondary colors.
Any two colors which when mixed in equal proportions produce white, are called complementary colors. From the above relationships, it can be seen that:
Magenta + Green = White
Yellow + Blue = White
Cyan + Red = White
And the pairs magenta/green, Yellow/Blue and Cyan/Red are examples of complementary colors.
2. Subtractive Color Mixing : Subtractive color mixing applies to the mixing of dyes and pigments and is the type of color mixing with which we are most familiar. Dyes and pigments absorb light most strongly in a characteristic region of the visible spectrum and reflect the rest of the light. The color of the reflected color is the color seen. For example, a magenta colored material absorbs light most strongly in the green region of the spectrum and reflects light in the blue and red regions, which together appears magenta. Thus of the original incident white light, the various regions of the spectrum are reflected to different extents by colored materials. The color of the light absorbed is the complementary color of the white light.
The term subtracting is used because color is subtracted or reduced from each color to produce black. The three primary colors are Red, Blue and Yellow. A mix of equal proportions of all three primaries produce Black.
Red + Yellow + Blue = Black