HTML
Color Codes: Understanding how they work
by
Joe Duchesne
Ever wonder how HTML color codes
are put together? For the beginner, it can look
like lots of numbers and letters that make no sense.
In reality, these color codes are written that
way for a specific reason that we'll look at in
this article.
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 Color
Codes in HTMLare put together
HTML Colors 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 amoung 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 color codes
found in HTML 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 look the way they
do.
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