With hex codes, a specific color is represented by a single code, which contains a combination of six letters and numbers. To change the three RGB values above into a single hex code, we'll need to make a few conversions. First take your first RGB number and divide that by 16. You can drop the remainder for now and just write down the whole number. This will be the first character in your hex code.
Introduction to the Hexadecimal System
In mathematics, the hexadecimal or simply hex is a numeral system with a base of 16 usually written using the symbols 0-9 and A-F. The numbers 0-9 have the same value as in the decimal system but starting with the letter A, the value keeps going up one up to the value of 16. A is worth 10, B is worth 11 and so forth until you get to F which is worth 16.
How the HTML Color Codes are put together
HTML Color codes are composed of six hex numbers that represent a possible 16.7 million color combinations. The hex color codes are built on the RGB color model. R stands for red, G for green, and B for blue. With your typical html code that looks like this: #FFFFFF it breaks down as follows. The first two hex digits #FFFFFF represent 'red'. The second set of two hex digits #FFFFFF represent the color green. The third and final set of two hex digits #FFFFFF represent the color blue.
A brief overview of the RGB model
The RGB color model, like the HTML color model can represent a total of 16.7 million colors. By varying the among of red, green, and blue, one can come up with any of 16.7 million colors. Each RGB value is represented by a number from 0 to 255. So a set of RGB values for the color white for instance, would look like this: 255, 255, 255.
Putting HTML and RGB Together
We've already established the hex numeral system with it's number range between 0 to 16. Now, when you combine two hex numbers, you can represent any number between 0 and 255. As you can see, RGB and HTML color codes represent the same color model.
Websafe Color Palette
Years ago, monitors could only display 256 colors. These monitors were still popular when HTML was first put together. As such, it was necessary to put together a list of colors that web designers could be sure any given monitor could properly display. Web safe colors are the result. The websafe color palette is made up of 216 colors.
It is always good practice to pick standard colors across the board, but it is no longer absolutely necessary to stick with web safe colors. Doing so now is more for purposes of holding to standard than it is for necessity. One exception to this rule may be developing websites for cellphones and PDA's. Having said that, these devices are now surpassing this barrier as well.
#FFFFFF represents the color white. #000000 represents the color black with every other color in between. I hope you now have a much better idea of why HTML color codes are look the way they do.
HTML Color Codes are 6 characters wide and look like "#80FF12", and are really 3 2-digit hex numbers that represent Red, Green, and Blue. Ok... I just lost a good portion of the crowd didn't I? Let's break it down into things that are easy to understand.
How to describe a color using numbers? There are a lot of ways to specify a particular color, but one of the ways that's used with computers is to specify the values of Red, Green, and Blue to mix together to achieve the desired color. As we vary the amounts of Red, Green, and Blue we can create most any color you desire.
How does this relate to computers? Computer displays, TVs, and other "projected light" display devices use pixels to display what you see on the screen and the color value for those pixels is specified in a RGB (Red, Green, Blue) value. For example if your monitor is set at 1024 x 768 resolution, then there are 768 lines (from top to bottom) on your screen, and each line has 1024 pixels or little dots in it. Each of those pixels or little dots is actually made of three smaller dots or light sources: a red one, a green one, and a blue one.
Ink works differently. Computer printers generally specify color as a four (or more) color "reflective" ink value made up of Yellow, Magenta, Cyan, and Black which is abbreviated as YMCK. The computer uses various formulas to convert the RGB values to CMYK values so that you can print what you see on your screen accurately.
How does the computer represent a RGB color value? HTML Color Code RGB values are stored as 3 separate values (one for Red, one for Green, and one for Blue) between 0 and 255. If you count the 0 as a value, then that's a total of 256 possible values. When you combine the Red, Green, and Blue values together to represent a color you get a possibility of 16.7 million colors (256 x 256 x 256). That's a lot of colors and most people consider this to be "true" color because it can represent most photographs and images accurately and naturally.
What is a Hex number? Your computer stores information as single ones and zeros. Each of these 0s and 1s is a single value called a "bit". When we combine 8 of these "bits"
together it makes a "byte". So therefore a byte is 8 bits.
We can count in various "bases". In regular everyday life, we use base 10 or "decimal". Base 10 uses these digits to represent a number: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. If we use the ones and zeros I just talked about, we're talking about just two possible values for each digit, 0 or 1, so this would be called base 2 or "binary". In computers, we use base 16, or hexadecimal (hex for short) a lot because it packs more values into a single space. Hex uses the following digits: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F. To represent the number 128 in decimal or base 10 requires 3 digits (128), in binary it requires 8 digits (10000000), and in hex or base 16 it requires just 2 digits (80). So by using hex values in programming, HTML, and other computer related things, we actually save storage space and gain efficiency.
If you're familiar with RGB, you know that a specific color is represented by a set of three different numbers: one for red (R), one for green (G), and one for blue (B). For example, the RGB values for a dark, grassy green might be:
R=77
B=131
G=50
R - 77 / 16 = 4.812 = 4 (first character in code)
Next take the remainder and multiply that by 16. Be sure to round up the final number. This will be the second character in your hex code.
.812 x 16 = 12.99 = 13 (second character in code)
But wait...13 can't be a single character in a hex color code. So we need to use a letter code instead. Numbers between 10 and 15 need to be replaced with the letters A through F (A=10, B=11, C=12, etc). In my example, that means the second character I came up with (13) will now be the letter "D." That makes the first character in my hex code look like this: 4D. That's better. Repeat the whole process above for each RGB number, and presto, you've converted RGB to Hex!
Article Source: http://EzineArticles.com/1090408How does this relate to HTML color codes? HTML colors codes are made up of 3 sets of hex numbers, one for Red, one for Green, and one for Blue.
For example:
000000 is black (0's for all three colors)
FFFFFF is white (255's for all three colors)
FF0000 is all RED (255 for Red, 0 green, 0 blue)
00FF00 is all GREEN (0 Red, 255 green, 0 blue)
0000FF is all Blue (0 red, 0 green, 255 blue)
FFFF00 is Yellow (255 red, 255 green, and 0 blue)
808080 is a gray (128 red, 128 green, and 125 blue)
Generally in HTML, you also put a "#" in front of the color code, but this is not necessary when you specify all 6 digits. If you make profiles for mySpace.com, leave off the "#" too because they filter them and it won't display the color correctly if you use the "#".
To convert between Decimal and Hex values, use the calculator that comes with Microsoft Windows. Open the calculator and select View and then Scientific. You'll see more buttons and controls on the calculator now. To convert a number from Hex to Dec, click on "Hex", key in the number, and then click "Dec".
