2.12 Hexadecimal Values: Where Do They Come From, and What Do They Mean?
Hexadecimal values consist of six total characters. These six characters can be broken down into three distinct groups of two:
- The first pair of values indicates the color’s degree of redness;
- The second pair of values indicates the color’s degree of greenness;
- The third pair of values indicates the color’s degree of blueness.
The hexadecimal system supports 256 unique shades of red, 256 unique shades of green, and 256 unique shades of blue. That may not sound like much, but together, these values can produce 256 * 256 * 256 = 16,777,216 total colors. That’s impressive!
Within each pair, the values range from 0 (total absence of that color) to 255 (strongest possible intensity for that color). In the hexadecimal system, the numbers 0 through 9 correspond to the numbers 0 through 9, just as they do in the numbering system that we use in everyday life. The letters A, B, C, D, E, and F are used to represent 10, 11, 12, 13, 14, and 15, respectively. Within each pair, the right-most value is in the 1s place, and the left-most member of the pair is in the 16s place (so we need to multiply that value by 16 to find its decimal value). We then add those two numbers together to arrive at the total value for that hexadecimal pair. 9
Let’s take a look at an actual hexadecimal value: #FF7F50. What does this actually mean? Let’s break it down, pair by pair.
The first pair of values is FF. Since F represents a value of 15 in the hexadecimal system, and that right-most F is in the 1s place, that’s 15. The left-most F, which is in the 16s place, holds a value of 16 x 15 = 240. We add them together to get 255, which is the highest ‘red’ intensity possible. If we only had this level of redness, with no green or blue values, the resulting color would look like this:
Now for that 2nd pair, 7F. This indicates our greenness. The right-most F, in the 1s place, has a value of 15. The 7, which is in the 16s place, holds a value of 16 x 7, or 112. Since 112+15 = 127, that’s our greenness intensity. This value by itself, without any redness or blueness, would look like this:
Okay, but we’re still not done with our color. The last pair of values is 50. With a 0 in the 1s place, that’s just 0. But that 5 in the 16s place is worth 16 x 5, or 80. Added together, that’s a “blueness” of 80 + 0 = 80. Here’s what that color would look like by itself, with no redness or greenness present:
With all three color pairs put together into the hexadecimal value ‘#FF7F50’ we arrive at the color shown below, which is sometimes referred to as ‘coral.’
Thankfully, you do not need to memorize any of this! There are many hexadecimal color pickers available on the web. A quick Google search for “hexadecimal color picker” will yield several options for sites that allow you to explore various shades to generate a color of your choice.
9 This is not very different from what we do in everyday life, with everyday numbers. Think about the number 82. What is it, really? We have an ‘8’ in the 10s place, and a ‘2’ in the 1s place. It’s the sum of eight 10s and two 1s. 80 + 2 = 82. With hexadecimal values, we are doing something similar, but with two differences: (1) the left-most digit is in the 16s place, rather than the 10s place; and (2) we have 16 different symbols to represent value, rather than 10.