Color Cube Exercisebeing revised May 2006
Gone are the days of limited colour representation on the web. Today true color is used most of the time. True color uses 256 grades in each of the red, green and blue spectrums. For heavy graphics process applications sometimes work better in high color which uses only 16 grades in each color, a total of about 64,000 colours.However it is instructive to look at the more restricted colour spectrum, that was once standard, of 6 grades corresponding to 00, 33, 66, 99, CC and FF in hexadecimal. This is an even distribution.
The colour spectrum can be represented by a cube. Stand the cude up on its point. Assign white (#FFFFFF) to the top apex, black (#000000) to the bottom point. Around the cube are six points, the three lower are red (#FF000000), green (#00FF00) and blue (#0000FF). The three points above are yellow (#FFFF00) which is the point above and between red and green, cyan (#00FFFF) which is the point above and between green and blue and the last is magenta (#FF00FF). The edges of the cube are divided into 6 cell divisions. Along each edge they make a progression from 00, 33, 66, 99, CC to FF for the single colour component which is changing along that edge.
This exercise is to represent the web colour cube in a two dimensional plan. There are two obvious alternatives for doing this and it is recommended that students in a class select either one so that the class can see a range of outcomes and decide which they like.
The cube can be treated as six slices of 6 by 6 cells which are connected along edges. The slices can be "unfolded" as though the cube had been made up of folded paper.
An alternative view is to look at the surface of the cube as though it were a paper box and unfold it. Having stripped off the 6 by 6 cube you are left with a 4 by 4 cube inside of greyer colours which are done the same way, and finally the innermost cube of 2 by 2 cells.
Use the image painter to make up grids representing the planes and fill the cells with the appropriate colour from the cube. Students may also wish to label key and favourite colours.
Compare results in class. Students will use different schemes for "unfolding" the planes and connecting them together. Ask students to discuss which schemes are most suitable for selecting colour schemes of coordinating colours, and for schemes which emphasise colour contrast for text and link text on background for example.