Hexadecimal

Hexadecimal code is, in effect, the lnaguage of computers and, although it may seem confusing, it's not significantly different from percentages, aside from how it's written.
When you used hexadecimal (or hex) to specify a color, you are still giving the rgb vales. The only difference is that the amounts are given through hexadecimal's base-16" numbering system.

For example, the browser-safe percentages in hex are as follows:
0%=00
20%=33
40%=66
60%=99
80%=cc
100%=ff
Thus, if you want to specify red in hex code, you simply begin with a hash mark (to identify the value as hexadecimal), then you supply,
100% red (ff)
0% green (00)
0% blue (00)

The complete value will look like this:
#ff0000.

However if you wants to have 80% red, the value will be written as:
#cc0000