Color Theory

Color Theory
Color Theory is a set of basic rules for mixing color to reach a desired result. Because color can be formed using both additive (RGB) and subtractive (CMYK) methods, two definitions, or color spaces, were developed to describe color. RGB RGB color is based on the light spectrum, and it breaks color down into an RGB representation. All color can be defined by a certain amount of R (red), G (green), and B (blue). Light emitting devices such as TVs and computer monitors function in this manner. If you were to turn off your monitor, you would see black because no R, G, or B colors are present. This would be written as RGB% 0,0,0. If you were looking at a white screen, you would be seeing RGB% 100,100,100 because each red, green, and blue light source is shining at full potential. Other colors are created by combining varying amounts of R, G, and B. True white light is composed of a full spectrum of all light colors, but RGB is close enough for most standards. RGB is an additive color space because you get white by adding all colors together. CMYK CMYK color is based on colorants; C (cyan), M (magenta), and Y (yellow) are used to create color. In theory, an equal amount of C, M, and Y would create K (black), but in practice the result is a muddy brown. Because of this, K is added to create pure blacks and other dark colors. K is also an economical solution since K ink is less expensive than C, M, and Y. CMYK is a subtractive color space because you get white by subtracting all colors. NOTE: RGB generally has a larger gamut than CMYK. This can create some problems when trying to accurately reproduce a color shown on your monitor. Device-Dependent Color Spaces Both RGB and CMYK are referred to as device-dependent color spaces because the colors defined in these spaces are intrinsically tied to the devices they were defined on. For example, each monitor and TV will have a slightly different color even though they display the same content because each monitor and TV has a slightly different color space. In a similar manner, each CMYK printer has a unique and slightly different color space. Because device-dependent color spaces cannot accurately be used with any other device-dependent color space, they require device-independent color spaces to convert color information. *Device-Independent Color Spaces (Lab)** Device-independent color spaces are mathematical color spaces used to interpret color between device-dependent color spaces. These color spaces use Lab. L represents the mathematical value of the lightness of a color; a* determines the mathematical red to green value; and b* determines the mathematical yellow to blue value. Because Lab* is a mathematical fixed standard, any defined value will always be accurate no matter the device. Lab* is used with ICC Profiles to ensure that color is accurate from the beginning to the end of your workflow. TIP: To learn more about Color Management go to this Thrive article and click the Maxi-imize tab.

Color Theory is a set of basic rules for mixing color to reach a desired result. Because color can be formed using both additive (RGB) and subtractive (CMYK) methods, two definitions, or color spaces, were developed to describe color.

RGB

RGB color is based on the light spectrum, and it breaks color down into an RGB representation. All color can be defined by a certain amount of R (red), G (green), and B (blue). Light emitting devices such as TVs and computer monitors function in this manner. If you were to turn off your monitor, you would see black because no R, G, or B colors are present. This would be written as RGB% 0,0,0. If you were looking at a white screen, you would be seeing RGB% 100,100,100 because each red, green, and blue light source is shining at full potential. Other colors are created by combining varying amounts of R, G, and B.

True white light is composed of a full spectrum of all light colors, but RGB is close enough for most standards.

RGB is an additive color space because you get white by adding all colors together.

CMYK

CMYK color is based on colorants; C (cyan), M (magenta), and Y (yellow) are used to create color. In theory, an equal amount of C, M, and Y would create K (black), but in practice the result is a muddy brown. Because of this, K is added to create pure blacks and other dark colors. K is also an economical solution since K ink is less expensive than C, M, and Y.

CMYK is a subtractive color space because you get white by subtracting all colors.

NOTE: RGB generally has a larger gamut than CMYK. This can create some problems when trying to accurately reproduce a color shown on your monitor.

Device-Dependent Color Spaces

Both RGB and CMYK are referred to as device-dependent color spaces because the colors defined in these spaces are intrinsically tied to the devices they were defined on. For example, each monitor and TV will have a slightly different color even though they display the same content because each monitor and TV has a slightly different color space. In a similar manner, each CMYK printer has a unique and slightly different color space.

Because device-dependent color spaces cannot accurately be used with any other device-dependent color space, they require device-independent color spaces to convert color information.

Device-Independent Color Spaces (L*a*b*)

Device-independent color spaces are mathematical color spaces used to interpret color between device-dependent color spaces. These color spaces use L*a*b*. L* represents the mathematical value of the lightness of a color; a* determines the mathematical red to green value; and b* determines the mathematical yellow to blue value. Because L*a*b* is a mathematical fixed standard, any defined value will always be accurate no matter the device.

L*a*b* is used with ICC Profiles to ensure that color is accurate from the beginning to the end of your workflow.

TIP: To learn more about Color Management go to this Thrive article and click the Maxi-imize tab.