ColorColor
Isaac Newton first studied light when he used a piece of glass and first saw the color spectrum.
The visible/color spectrum is the ordered arrangement of colors by wavelength and frequency
Spectrum
Color by Reflection Different objects reflect (if material is opaque) and absorb (if the material is transparent)
Color by Transmission The color of a transparent object depends on the color of the light it transmits The material in glass that selectively absorbs colored light is pigment. Glass is colorless since it transmits all visible frequencies.
(examples-the 3 pixels in your TV) Secondary-the result of mixing 2 primary colors Red + Blue = Magenta Blue + Green = Cyan Red + Green = Yellow Light-there are primary and secondary colors of light Primary-Red, Blue, Green
Adding colors of light is called Color by Addition White-addition of all colors of the visible spectrum, or by adding the 3 primary colors Black-absence of light, all 3 lights are blocked
ADDITION OF PRIMARY COLORS When paints or dyes are mixed, the mixture absorbs the frequencies of the paint or dye
Complementary colors of light- two colors which when added, create white light Blue + Yellow = White Red + Cyan = White Green + Magenta = White So…yellow light is the complementary color to blue light
A Pigment is a colored material that absorbs certain wavelengths of light (certain colors) and transmits or reflects others---Think PAINT
Primary Pigment-A pigment that absorbs only one primary color from white light Yellow (absorbs blue light) Cyan (absorbs red light) Magenta (absorbs green light)
Secondary Pigment-A pigment that absorbs two primary colors and reflects one Red (absorbs green & blue) Blue (absorbs red & green) Green (absorbs red & blue)
PRACTICE
Answers to Practice Addition of Primary Colors Red + Green = Yellow Red + Blue = Magenta Blue + Green = Cyan
Color by subtraction~the pigment is ‘taking out’ / ‘subtracting’ / ‘absorbing’ a color of light Complementary Pigments-two colors that when added, will absorb all colors of the spectrum (‘black’ pigment is made) minimal/no light is reflected
Think Mixing Paint… yellow + blue = black cyan + red = black magenta + green = black
PRACTICE
Answers to Practice Practice A- Magenta is red + blue. Blue is subtracted (absorbed) so that leaves red, shirt appears red Practice B-red is a primary color, blue is subtracted (absorbed) so it is not present, so shirt appears red Practice C-Blue is a primary color, blue is subtracted (absorbed) so no color is left, shirt appears Black
Why? …is the sky blue Blue is scatted the most during the middle of the day, due to its high frequency and low energy …are sunsets red Red, orange, and yellow are scattered more during this time, so red is refracted more, so red, orange, etc if seen
Do problem set in class