RGB Color Model


The RGB Color Model is used a lot. It is used in both HTML and in The GIMP. Look at the source for this page and you will see color specified using RGB values several times. The R in RGB stands for RED. The G in RGB stands for GREEN. The B in RGB stands for BLUE.

RGB values are often stated as HEX values. HEX is short for hexadecimal (or base 16). The hexadecimal system uses the following digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, and F. The letter digits have the following values:


This can be a little confusing, but you don't really need to understand the hexadecimal number system thoroughly to be able to use it to specify color. All you have to remember is that the first two digits are the RED digits, the second two digits are the GREEN digits, and the last two digits are the BLUE digits. The maximum value for each pair is FF (decimal value 255) and the minimum value is 00 (decimal value 00). Inspect the code for this paragraph to see how the RGB values were used in the FONT tag to specify color.

The GIMP's dialog box for color selection displays the HEX values for the color you select. If you use a slider for R, G, or B the resulting value is displayed to the right, BUT at the bottom the HEX TRIPLET is also displayed and automatically updated.
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ASSIGNMENT: For this assignment you will create a six column table. Your column headings will be COLOR_NAME, RED, GREEN, BLUE, HEX TRIPLET, and SAMPLE. Under the RED, GREEN, and BLUE columns you will place the decimal value for that component of the color (the name of which will appear, obviously in the COLOR_NAME column). The HEX TRIPLET column will hold the six digit hex values. The SAMPLE column will hold small sample images for each color included in the table. Here are the colors you must use: red, green, blue, yellow, magenta, cyan, and purple. You must set the background color for your page to white (using HEX values). You must create your sample images in The GIMP. They will be small squares of one color. You will save these images as JPGs.