Basic Color Theory
12 Basic hues (colors) 3 Primary, 3 Secondary, 6 Tertiary
Color Wheel
An illustrative circular graph that shows the relationship of colors to each other.
Spectrum (the visible Spectrum)
The range of visible colors in nature. The colors (Hues) of the spectrum are traditionally listed
as, Red, Orange, Yellow, Green, Blue, Indigo, Violet. Or ROY G BIV
Hue (color)
Hue is the technical/traditional color name, i.e. Red, Blue, Yellow Green. A
Value
The degree of light or dark present in a color. Another way to think of this is how much
white or black is present, or mixed into the color. The normal value would be how that
color appears on the spectrum.
Normal Value
A normal value is equal to the Hue and is the value of a color as it appears naturally in
the spectrum
Tint
Tint is the term used to describe a hue(color) that has been lightened in Value from its
normal value
Shade
Shade is the term used to describe a hue(color) that has been darkened in Value from its
normal value
Tone
A hue of reduced intensity/saturation
A tone of a hue is created in two ways;
1. By adding a neutral gray, equal in value to the hue. For example, a light gray
added to yellow or a medium gray added to red or a dark gray added to violet.
2. By adding its complement.
Tones that have their intensity reduced almost to the point of appearing gray
are referred to as a Chromatic Gray
Saturation
Also called Chroma this is the intensity or purity of a color. The highest
intensity/saturation of given hue/color is the color as it appears naturally in the spectrum
Primary Colors
Color as Pigment (subtractive color theory) - Red Blue Yellow, These are colors which
cannot be made by blending other colors.
Pigment A substance used to make a color.
In Subtractive Color Theory. Color is the result of light being absorbed.
Color as Light (Additive Color Theory) – Red, Blue, Green
In Additive Color Theory Color appears as a combination of light
Secondary Colors
Those Colors made by the combination of two primary colors.
Complimentary Colors
The complimentary color of any color is the color that appears directly opposite it on the
color wheel. In color theory, the blending of these two colors in the right in equal
proportion should result in a neutral color, usually grey.
Palette/ Color Palette
The specific range of colors being used or allowed.
RGB
The Primary colors of Light. This is what we see on our monitors and TVs, phones, pads
etc.
CYMK
Also known as process color, or 4 color, 4 color process.
Standard Print Palette. Cyan, Magenta, Yellow, Black
RGB
RYB
CYM
In RGB, all of the colors combined = white. The Absence of Color is Black
In CYMK, the K stands for Black. Or sometimes Keyed to Black. Theoretically, the
combination of CYM should result in a pure black. However, in the real world the inks don’t
quite get to the level of perfect, and as you can see the best that can usually be achieved is a very
dark brown/gray. So black ink is added, thus the 4 color process as opposed to just 3.
RGB Color Mode
RGB images use three colors, or channels, to reproduce colors on screen.
Although RGB is a standard color model, the exact range of colors represented can vary,
depending on the application or display device. The RGB Color mode in Photoshop varies
according to the working space setting that you specify in the Color Settings dialog box
CMYK Color mode
In the CMYK mode, each pixel is assigned a percentage value for each of the
process inks. The lightest (highlight) colors are assigned small percentages of
process ink colors; the darker (shadow) colors higher percentages. For example, a
bright red might contain 2% cyan, 93% magenta, 90% yellow, and 0% black. In
CMYK images, pure white is generated when all four components have values of
0%.
Use the CMYK mode when preparing an image to be printed using process
colors. Converting an RGB image into CMYK creates a color separation. If you
start with an RGB image, it’s best to edit first in RGB and then convert to CMYK
at the end of your editing process. In RGB mode, you can use the Proof
Setup commands to simulate the effects of a CMYK conversion without
changing the actual image data. You can also use CMYK mode to work directly
with CMYK images scanned or imported from high-end systems.
Although CMYK is a standard color model, the exact range of colors represented
can vary, depending on the press and printing conditions. The CMYK Color
mode in Photoshop varies according to the working space setting that you specify
in the Color Settings dialog box.
Indexed Color mode
Indexed Color mode produces 8-bit image files with up to 256 colors. When
converting to indexed color, Photoshop builds a color lookup table (CLUT),
which stores and indexes the colors in the image. If a color in the original image
does not appear in the table, the program chooses the closest one or
uses dithering to simulate the color using available colors.
Although its palette of colors is limited, indexed color can reduce file size yet
maintain the visual quality needed for multimedia presentations, web pages, and
the like. Limited editing is available in this mode. For extensive editing, you
should convert temporarily to RGB mode. Indexed color files can be saved in
Photoshop, BMP, DICOM (Digital Imaging and Communications in Medicine),
GIF, Photoshop EPS, Large Document Format (PSB), PCX, Photoshop PDF,
Photoshop Raw, Photoshop 2.0, PICT, PNG, Targa®, or TIFF formats.