A color wheel is an illustrative model of color hues around a circle. It shows the relationships between the primary, secondary, and intermediate/ tertiary colors and helps demonstrate color temperature. Digital teams communicate exact colors through the use of hex codes.
Green, the fourth primary color?
The questions that drive scientific research seem to strike when you least expect.
I took my two children to Legoland in Carlsbad, California recently. As we approached the entrance, I noticed four giant Lego blocks greeting us; they were red, yellow, blue, and green. This got me thinking about colors.
Yes, there is an additive system of three primary colors — red, green, and blue: the colors of light — but let’s set that aside for a moment. In the subtractive system (the one that dominates our kindergartens), the three primary colors are red, blue and yellow; and their associated secondary colors are orange, purple, and green. Yet, whenever four colors are displayed, green is the fourth color — open up a small four-pack of Crayola crayons to see for yourself. One rarely finds red, blue, and yellow displayed with the other two secondaries: orange or purple. Why is this?
The retina has cone-like structures that are receptive to light. The cones are labeled according to their sensitivity to wavelengths. They are called short, medium, and long cones. Studies have shown that the peak sensitivity of long cones is in the greenish-yellow region of the spectrum; and both the short and medium cones are also highly sensitive to green. So, by and large, we are very sensitive to green. So perhaps that is why, when four colors are displayed, green is often the fourth. Green is simply more attractive to our eyes.
But why are we sensitive to green? One can only guess. Foliage is most often green, so one would imagine that early man would have to become very sensitive to the various hues of green to determine if any danger lurked in the dark or light green underbrush. Anyone without sensitivity to green may have been gobbled up. There may be a more substantive reason, but the balance is interesting.
But then one asks why, of all the colors, is it green that is reflected by chlorophyll? I don’t know; but the point in science is to ask, to ponder, to wonder.
Color Temperature
The colors on the red side of the wheel are warm; the green side of the wheel has the cooler colors. These color temperature designations are absolute. More subtle color temperature relationships are relative, meaning that each color on the warm side of the wheel can be known as cool, and colors on the cools side of the wheel can be known as warm depending on the relationship to their neighboring color. Colors from the same hue, for instance red, can also be warmer or cooler than one another.
Color temperatures affect us both psychologically and perceptually by helping us determine how objects appear positioned.
- Warm colors include red, orange, and yellow, and variations of those three colors.
- Red and yellow are both primary colors, with orange falling in the middle.
- Warm colors appear closer to the observer.
- Cool colors include green, blue, and purple, and variations of those three colors.
- Blue is the only primary color within the cool spectrum.
- Greens take on some of the attributes of yellow, and purple takes on some of the attributes of red.
- They are often more subdued than warm colors.
- Cool colors appear farther from the observer.
Neutrals
Neutral colors include black, white, gray, tans, and browns. They’re commonly combined with brighter accent colors but they can also be used on their own in designs. The meanings and impressions of neutral colors depend more so upon the colors around them.
There are two models for colors. They have different purposes and different attributes. They are as follows:
- CMYK Color Models: Stands for cyan, magenta, and yellow. It applies to painting and printing. The CMYK model is a subtractive model, meaning that colors are created through absorbing wavelengths of visible light. The wavelengths of light that don’t get absorbed are reflected, and that reflected light ends up being the color we see.
- RGB Color Models: RGB stands for red, green, and blue. It applies to computers, televisions, and electronics. The RGB model is an additive model, meaning that colors are created through light waves that are added together in particular combinations in order to produce colors.
Hex Codes
To name colors in web design, teams use hexadecimal code. All hexadecimal codes:
- Start with a hash mark (#)
- Consist of three pairs of characters sequenced together (totaling of six characters), with each pair controlling one of the primary additive colors (red, green, blue)
- Those six characters following the hash mark consist of ten numerals (0-9) and/ or six letters (a-f)
It is easy to identify patterns in the hex codes some colors; see SmashingMagazine’s great chart at the right for this. Some things to know include:
- 00 is a lack of primary
- ff is the primary at full strength
To find additive colors, start with black and change each pair to ff:
- #000000 is black (no primaries)
- #ff0000 is the brightest red
- #00ff00 is the brightest green
- #0000ff is the brightest blue
To find subtractive colors, start with white and change each pair to 00:
- #ffffff is white (all primaries
- #00ffff is the brightest cyan
- #ff00ff is the brightest magenta
- #ffff00 is the brightest yellow
It is also possible to abbreviate some hex numbers. For instance, #fae expands to #ffaaee and #09b expands to #0099bb.
