Intro to Color Theory. Objectives Identify and discuss various color models including RGB, CMYK, Black/white and spot color. Investigate color mixing.

Introto Color Theory

ObjectivesObjectives

• Identify and discuss various color models including RGB, CMYK, Black/white and spot color.

• Investigate color mixing processes.• Apply color mixing processes to

create new colors in digital format using various software tools.

Typical Color ModelsTypical Color Models

• H-S-B (or V)• R-G-B • C-M-Y-K

(Black)• Black & White• Spot Color

Visible Light SpectrumVisible Light Spectrum

Glass Prism

WhiteSunlight

"Spectral Colors"

Color AttributesColor Attributes

• A Theoretical Approach• Characteristics of Color

– Hue– Brightness– Saturation

Hue - Perceived as Hue - Perceived as “Color”“Color”

Brightness - Amount of Brightness - Amount of Perceived “White” in a HuePerceived “White” in a Hue

Saturation - Amount of Saturation - Amount of Perceived “Black” in a HuePerceived “Black” in a Hue

Hue CircleHue Circle

Brightness orBrightness or“Gray” Scale“Gray” Scale

White

Black

256 LevelsOf Brightness

Zero Units

255 Units

Hue and BrightnessHue and Brightness

Additive Color Mixing Additive Color Mixing and the and the

R-G-B Color R-G-B Color ModelModel

Additive Color MixingAdditive Color Mixing

• Used for mixing colors created by light.– Video Cameras– Computer

Screens– Television

Lights– Video Monitors

Additive Color MixingAdditive Color Mixing

• Three primary colors:– Red– Green – Blue

• This is the R-G-B color model.

Additive Color MixingAdditive Color Mixing

• Assuming a “pure” hue.

• Equal amounts of red and blue yields magenta.

Additive Color MixingAdditive Color Mixing

• Assuming a “pure” hue.

• Equal amounts of red and green yields yellow.

Additive Color MixingAdditive Color Mixing

• Assuming a “pure” hue

• Equal amounts of blue and green yields cyan.

Additive Color MixingAdditive Color Mixing

• Assuming a “pure” hue.

• When all three overlap, they “add up” to white!

Brightness orBrightness or“Gray” Scale“Gray” Scale

White

Black

256 LevelsOf Brightness

Zero Units

255 Units

How Many Colors?How Many Colors?

Zero Units of Red = Black

255 Units of Red = Pure Red

Color has 256 levels from0 to 255.

256 Possible Reds!

How Many Colors?How Many Colors?

The R-G-B Model can mix.

Any of 256 shades of red.Any of 256 shades of green.Any of 256 shades of blue.

Yielding a possible16,777,216 colors!

Digital “Math”Digital “Math”21 = Black & White

29 = 512 217 = 131072

22 = 4 colors 210 = 1024 218 = 262144

23 = 8 colors 211 = 2048 219 = 524288

24 = 16 colors 212 = 4096 220 = 1048576

25 = 32 colors 213 = 8192 221 = 2097152

26 = 64 colors 214 = 16384 222 = 41194304

27 = 128 colors 215 = 32768 223 = 8388608

28 = 256 colors 216 = 65536 224

=16777216

Digital “Math”Digital “Math”21 = Black & White

29 = 512 217 = 131072

22 = 4 colors 210 = 1024 218 = 262144

23 = 8 colors 211 = 2048 219 = 524288

24 = 16 colors 212 = 4096 220 = 1048576

25 = 32 colors 213 = 8192 221 = 2097152

26 = 64 colors 214 = 16384 222 = 41194304

27 = 128 colors 215 = 32768 223 = 8388608

28 = 256 colors 216 = 65536 224

=16777216

Digital “Math”Digital “Math”21 = Black & White

29 = 512 217 = 131072

22 = 4 colors 210 = 1024 218 = 262144

23 = 8 colors 211 = 2048 219 = 524288

24 = 16 colors 212 = 4096 220 = 1048576

25 = 32 colors 213 = 8192 221 = 2097152

26 = 64 colors 214 = 16384 222 = 41194304

27 = 128 colors 215 = 32768 223 = 8388608

28 = 256 colors 216 = 65536 224

=16777216

Digital “Math”Digital “Math”21 = Black & White

29 = 512 217 = 131072

22 = 4 colors 210 = 1024 218 = 262144

23 = 8 colors 211 = 2048 219 = 524288

24 = 16 colors 212 = 4096 220 = 1048576

25 = 32 colors 213 = 8192 221 = 2097152

26 = 64 colors 214 = 16384 222 = 41194304

27 = 128 colors 215 = 32768 223 = 8388608

28 = 256 colors

216 = 65536 224

=16777216

Digital “Math”Digital “Math”21 = Black & White

29 = 512 217 = 131072

22 = 4 colors 210 = 1024 218 = 262144

23 = 8 colors 211 = 2048 219 = 524288

24 = 16 colors 212 = 4096 220 = 1048576

25 = 32 colors 213 = 8192 221 = 2097152

26 = 64 colors 214 = 16384 222 = 41194304

27 = 128 colors 215 = 32768 223 = 8388608

28 = 256 colors 216 = 65536 224

=16777216

Digital “Math”Digital “Math”21 = Black & White

29 = 512 217 = 131072

22 = 4 colors 210 = 1024 218 = 262144

23 = 8 colors 211 = 2048 219 = 524288

24 = 16 colors 212 = 4096 220 = 1048576

25 = 32 colors 213 = 8192 221 = 2097152

26 = 64 colors 214 = 16384 222 = 41194304

27 = 128 colors 215 = 32768 223 = 8388608

28 = 256 colors 216 = 65536 224

=16777216

Saturation andSaturation andBrightnessBrightness

Saturation = 255 unitsBrightness = 128 units

Saturation and Saturation and BrightnessBrightness

Saturation = 0 unitsBrightness = 128 units

Subtractive Color Mixing Subtractive Color Mixing and the and the

C-Y-M-K Color C-Y-M-K Color ModelModel

Subtractive Color MixingSubtractive Color Mixing

• Used for mixing inks for printing.

• Primary colors are:– Yellow– Cyan– Magenta

Subtractive Color MixingSubtractive Color Mixing

• Assuming a “pure” hue.

• Equal amounts of cyan and magenta yields blue.

Subtractive Color MixingSubtractive Color Mixing

• Assuming a “pure” hue.

• Equal amounts of magenta and yellow yields red.

Subtractive Color MixingSubtractive Color Mixing

• Assuming a “pure” hue.

• Equal amounts of cyan and yellow yields green.

Subtractive Color MixingSubtractive Color Mixing

• Assuming a “pure” hue.

• When inks are mixed, the color filters or “subtracts” out yielding black.

Subtractive Color MixingSubtractive Color Mixing

• When mixing inks or pigments, you never achieve a true black.

• Black requires a special black mixture.

Spot ColorSpot Color

• Use of one color for printing purposes.– Business

cards– Clip art– Logos

Spot ColorSpot Color

Usually a single color is added to black as in this example. Different values of the same hue can be used.

Changing Colors in Changing Colors in Graphics SoftwareGraphics Software

Changing ColorsChanging Colors

Click on foreground

Color to launch“Color Picker”.

Changing ColorsChanging Colors

Changing ColorsChanging Colors

Changing ColorsChanging Colors

Changing ColorsChanging Colors

Curriculum Content andCurriculum Content andActivities created byActivities created byDr. Mark MortensenDr. Mark Mortensen

Dept. of Technology & CognitionDept. of Technology & CognitionUniversity of North TexasUniversity of North Texas

Copyright C. Mark Mortensen 2001