How we change what others think, feel, believe and do
Twelve Color Wheel
Colors can be described in several ways, such as with the classic 'spectrum'. They can also be arranged in a circle (this was first noticed by Isaac Newton). The arrangement can be very helpful when choosing colors for a color scheme.
The 12-color wheel is a common structuring of hues that is based in paint and light and is hence popular with artists as well as photographers. The hues can be arranged in a circle, which is convenient for combinations as described below. The names for hues can vary (as indicated below).
Note that there are a number of other schemes of 12 hues that, although similar are different in various ways. The 12-color wheel shown here is based on classic digital division of hues. There are also a number of different names for the same colors.
Warm and cool
A line can be drawn across the wheel roughly separating those hues which can be considered warmer from those which are cooler. Warmer hues are more dominant as they stand out more, while cool hues tend to recede and be noticed less. Warm is associated with daylight, action, emotion, while cool is associated more with night, calm, reason. In graphic design, this difference can be used for example in separating headlines from sub-text.
Lightness of a color is the perceived brightness. Hence, we see yellow as brighter than blue, even though they are both fully saturated. These can be measured and hence sequenced in terms of lightness. This is useful when you want colors to stand out, especially if they may be rendered in grayscale. With constant saturation and lightness, converted to grayscale, luminance is:
The primary hues are Red, Green and Blue (RGB). They are sometimes called the 'electronic colors' as they are used to display hues in electronic devices where RGB dot clusters are used to create all other colors. They are hence referred to as 'additive' hues.
The secondary hues are Cyan (or Aqua), Magenta (or Fuscia) and Yellow (together known as CMY or, with black, CMYK). They are 'opposites' of RGB and can be created with lights by shining the adjacent primary colors together (hence red light and green light make yellow light).
Secondary hues are sometimes called 'printer's colors' as they are used in printer pigment inks and are combined to create all other colors on printers. They are hence referred to as 'subtractive' hues. Printers also use black (K, to differentiate from Blue) as it is very difficult to mix CMY to get a pure black.
Tertiary hues make up the remaining colors in the wheel, with Orange, Chartreuse Green (or just Chartreuse or Yellow Green), Spring Green (or Blue Green), Azure (or Blue Violet), Violet, and Rose (or Red Violet). They are made by mixing adjacent primary and secondary colors.
It is possible to extend the number of hues around the wheel ad infinitum by combining adjacent hues, thereby doubling the total number on each pass through this process.
Artists use subtractive primary hues of Red, Yellow and Blue. A similar 12-color wheel can be constructed using these, as below. Note how this is subtly similar and different to the additive RGB wheel above, though with an expanded Red-Yellow section (and correspondingly reduced Green-Blue section). The secondary hues of Orange, Green and Purple are of course probably quite familiar to most people who grew up using physical paints.
Note that the wheel starts and ends with the same hue (typically, red is used for end-stops when shown as a linear spectrum). This is different to the Newtonian, frequency-based, optical spectrum that starts with red and ends with indigo (as seen in a rainbow).
Use this wheel to help select colors. Remember that you can use desaturated versions of any hue and any combination of hues in between.