CMYKCMYK

• CyanCyan

• MagentaMagenta

• YellowYellow

• BlackBlack

CMYK and RGB ColorCMYK and RGB Color

CMYKCMYK

CMYKCMYK

CMYKCMYK

• CMYKCMYK (short for (short for ccyan, yan, mmagenta, agenta, yyellow, ellow, and and kkey (Blacey (Blackk), and often referred to as ), and often referred to as process colorprocess color or or four colorfour color) is a ) is a subtractive color model, used in , used in color printing, also used to describe the , also used to describe the printing process itself. printing process itself.

• Such a model is called Such a model is called subtractivesubtractive because inks because inks ““subtractsubtract”” brightness from from white. white.

RGBRGB

• RedRed

• GreenGreen

• BlueBlue

RGBRGB

RGBRGB

• The The RGB color modelRGB color model is an is an additive model in which in which red, , green, and , and blue (often used in (often used in additive light models) are combined in additive light models) are combined in various ways to reproduce other various ways to reproduce other colors. .

• The name of the model and the The name of the model and the abbreviation abbreviation ‘‘RGBRGB’’ come from the three come from the three primary colors, red, green, and blue and , red, green, and blue and the technological development of the technological development of cathode ray tubes which could display color which could display color instead of a monochrome phosphoresence instead of a monochrome phosphoresence (including grey scaling) such as black and (including grey scaling) such as black and white film and television imaging. white film and television imaging.

CMYK vs RGBCMYK vs RGB

• CMYK = printingCMYK = printing

• RGB = on screenRGB = on screen

CMYK vs RGBCMYK vs RGB

• In In additive color models such as models such as RGB, white is , white is the the ““additiveadditive”” combination of all primary combination of all primary colored lights, while black is the absence of colored lights, while black is the absence of light. light.

• In the CMYK model, it is just the opposite: In the CMYK model, it is just the opposite: white is the natural color of the paper or white is the natural color of the paper or other background, while black results from a other background, while black results from a full combination of colored inks. full combination of colored inks.

• To save money on ink, and to produce deeper To save money on ink, and to produce deeper black tones, unsaturated and dark colors are black tones, unsaturated and dark colors are produced by substituting black ink for the produced by substituting black ink for the combination of cyan, magenta and yellow. combination of cyan, magenta and yellow.

CMYK vs RGBCMYK vs RGB

• Comparisons between RGB displays and CMYK prints Comparisons between RGB displays and CMYK prints can be difficult, since the color reproduction can be difficult, since the color reproduction technologies and properties are so different. technologies and properties are so different.

• A laser or ink-jet printer prints in dots per inch (dpi) A laser or ink-jet printer prints in dots per inch (dpi) which is very different from a computer screen, which is very different from a computer screen, which displays graphics in pixels per inch (ppi). which displays graphics in pixels per inch (ppi).

• A computer screen mixes shades of red, green, and A computer screen mixes shades of red, green, and blue to create color pictures. blue to create color pictures.

• A CMYK printer must compete with the many shades A CMYK printer must compete with the many shades of RGB with only one shade of each of cyan, of RGB with only one shade of each of cyan, magenta and yellow, which it will mix using magenta and yellow, which it will mix using dithering, halftoning or some other optical dithering, halftoning or some other optical technique; this dithering produces a lower level of technique; this dithering produces a lower level of detail than the printer's dpi suggests. detail than the printer's dpi suggests.

Color spacesColor spaces

• Color is typically organized in a hierarchal fashion, based on Color is typically organized in a hierarchal fashion, based on how colors are mixed. A color space helps to define how the how colors are mixed. A color space helps to define how the colors are mixed, based on the medium in which the colors colors are mixed, based on the medium in which the colors are used. There are two different kinds of color spaces:are used. There are two different kinds of color spaces:

Subtractive AdditiveSubtractive Additive

ColorColor

• Color is the response of the eye to differing Color is the response of the eye to differing wavelengths of radiation within the visible wavelengths of radiation within the visible spectrum. The visible spectrum is what we spectrum. The visible spectrum is what we perceive as light. It is the part of the perceive as light. It is the part of the electromagnetic spectrum that we can see. electromagnetic spectrum that we can see. The typical human eye will respond to The typical human eye will respond to wavelengths between 400-700 nanometers wavelengths between 400-700 nanometers (nm), with red being at one end (700 nm), (nm), with red being at one end (700 nm), violet at the other (400 nm) and every violet at the other (400 nm) and every other color in between these two. other color in between these two.

ColorColor

• There are many different kinds of color systems, and many There are many different kinds of color systems, and many different theories on color. We will get into that kind of different theories on color. We will get into that kind of detail in a later column. For now we will focus on the basics, detail in a later column. For now we will focus on the basics, using a color wheel for illustration purposes. There are using a color wheel for illustration purposes. There are three main components of color:three main components of color:

• HueHue: Where the color is positioned on the color wheel. : Where the color is positioned on the color wheel. Terms such as red, blue-green, and mauve all define the Terms such as red, blue-green, and mauve all define the hue of a given color. hue of a given color.

• ValueValue: The general lightness or darkness of a color. In : The general lightness or darkness of a color. In general, how close to black or white a given color is. general, how close to black or white a given color is.

• SaturationSaturation: The intensity, or level of chroma, of a color. : The intensity, or level of chroma, of a color. The more gray a color has in it, the less chroma it has. The more gray a color has in it, the less chroma it has.

Hue, Value and SaturationHue, Value and Saturation

Color HarmoniesColor Harmonies

AnalagousAnalagous ComplimentarComplimentaryy

TriadiTriadicc

Color HarmoniesColor Harmonies

• Color harmonies serve to describe the relationships certain colors Color harmonies serve to describe the relationships certain colors have to one another, and how they can be combined to create a have to one another, and how they can be combined to create a palette of color.palette of color.

• ComplementaryComplementary: A complementary relationship is a harmony of : A complementary relationship is a harmony of two colors on the opposite side of the color wheel. When two colors on the opposite side of the color wheel. When complementary colors are placed side-by-side they tend to complementary colors are placed side-by-side they tend to enhance the intensity (chroma) of each other, and when they are enhance the intensity (chroma) of each other, and when they are blended together they tend to decrease the intensity of each blended together they tend to decrease the intensity of each other. other.

• AnalogousAnalogous: An analogous relationship is a harmony of colors : An analogous relationship is a harmony of colors whose hues are adjacent to one another on the color wheel. whose hues are adjacent to one another on the color wheel. Analogous colors tend to be families of colors such as blues (blue, Analogous colors tend to be families of colors such as blues (blue, blue-violet, blue-green) and yellows (yellow, yellow-orange, blue-violet, blue-green) and yellows (yellow, yellow-orange, yellow-green). yellow-green).

• TriadicTriadic: A triadic relationship is a harmony of three colors : A triadic relationship is a harmony of three colors equidistant from one another on the color wheel. Primary colors equidistant from one another on the color wheel. Primary colors and secondary colors are examples of color triads. and secondary colors are examples of color triads.