Color Mixing. Color Systems and Additive and Subtractive Colors. MODIFIED FROM Dr. Patricia Hill, Millersville University

Transcription

1 Color Mixing Color Systems and Additive and Subtractive Colors MODIFIED FROM Dr. Patricia Hill, Millersville University

2 Describing Color

3 Color Attributes Hue (color) Brightness Saturation or Purity corresponds to wavelength corresponds to amplitude corresponds to Monochromaticity of colored light Blue hue at various levels of saturation Blue hue at various levels of brightness

4 Systems for Quantifying Color Three Systems (of many) Munsell Color System CIE Chromaticity Diagram L.A.B. Color System Numerical quantification of color Allows for precise matching of colors in printing and dye industries

5 The Munsell Color Tree Arranges colors according to hue, brightness, and saturation Brightness White Hue Saturation Black

6 Munsell Color System brightness saturation

7 The CIE Chromaticity Diagram Hues on perimeter Saturation levels decrease internally

8 Chromaticity vs. Gamut We cant see everything We cant create everything! There is a limited gamut of colors in a monitor Each monitor is slightly different

9 L.A.B. Color System L = lightness a = red-green b = blue-yellow

10 Two Types of Color Mixing Subtractive Color Mixing More familiar type Mixing of paints, dyes, inks Additive Color Mixing Mixing of colored lights

11 Colored Pigments as Microfilters Colored pigments + binder = paint Pigment particles act as tiny colored filters Binder Pigment particle Ground

12 Colored Pigments as Microfilters

13 Analysis of wallpapers in Colonial Williamsburg

14 CSI: real or fake? Rice starch was a common binder in earlier wallpapers. It shows a nice pattern under polarized light

15 CSI: real or fake? Old papers were not made of paper pulp from trees (<1900)

16 CSI: real or fake? Modern papers do have pulp from pine trees (conifers)

17 Pigments as Colored Filters yellow blue red Primary Subtractive Colors white light

18 Subtractive Color Mixing Mixing of paints Y B R Primary colors G V O Complementary colors formed by mixing 2 primary colors

19 Complementary Colors The Zouave, 1888 Vincent van Gogh (Dutch ) green & red Use of complementary colors by Impressionist painters. blue & yellow

20 Complementary colors

21 Dullness of black and white Paul Cezanne, "Still Life, Drapery, Pitcher, and Fruit Bowl"

22 Monet early work

23 What happens if you mix... 3 subtractive primary colors??? R + B + Y = A primary with its complementary? R + G =??? B + O =??? Y + V =??? yellow Making blacks. Dark Brown or Black white light blue red

24 Confused yet?

25 Key Concepts Subtractive Mixing of pigments, inks, dyes, paints Each pigment selectively absorbs (subtracts out) certain colors (wavelengths) of light Mixing of pigments decreases amount of light transmitted Can lead to muddy colors

26 Printer s Subtractive Colors CYMK Cyan (blue) Yellow (yellow) Magenta (red) Black (K)

27 Additive Color Mixing Characterized by mixing of colored lights Additive primary colors are... Red (R) Green (G) Blue (B)

28 Additive Color Mixing

29 Complementary Additive Colors Formed by the mixing of 2 primary colors R + B = M B + G = C R + G = Y

30 Key Concepts Additive Each light adds certain wavelengths of light to the mix (color) Mixing of lights increases the total amount of light transmitted Mixed lights are brighter

31 What Happens if You Mix... 3 additive primary colors? White Light R + B + G = 2 additive complementary colors? C + Y =??? Y + M =??? C + M =???

32 Color Mixing blue (B+G) + (B+R) = B cyan yellow magenta (B+G) + (G+R) = G (R+G) + (B+R) = R green red

33 Mixing of Primary Colors White light Black

34 Illuminated Colored Objects White Light Blue

35 In Red Light Blue

36 In Blue Light Blue

37 In Green Light Blue

38 In Yellow Light Blue

39 Maxwell Disks James Clerk Maxwell ( ) Rapidly spinning disks with two colored halves Vision persistence blends the colors

40 Pointillist Movement Sunday Afternoon on the Island of La Grande Jatte (1886) Chicago Art Institute George Seurat ( )

41 Pointillism George Seurat Neoimpressionist painter La Poudreuse (Madeleine Knobloch) 1889

42 Close-up of Seurat Painting Tiny dots of color Blended by the eye of the observer Additive color mixing

43 Y M C = = R B R + + G B W = R + G + B

44 Colors in your TV and Computer Examine screen with magnifier RGB phosphors Additive color mixing of lights

45 Four-Color Process Printing CYMK Cyan (blue) Yellow (yellow) Magenta (red) Black

46 The Moire Effect Overlapping of two or more images of closely spaced lines

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