Tutoring web graphics to myself, this was an early curiosity.
Html colors can be expressed as rgb(0-255, 0-255, 0-255): the first number is for red, the second green, the third blue. Red, for instance, is rgb(255,0,0).
Interestingly, brown can be seen as dark red from an html point of view. That is, if you just cut down the red, keeping the other colors at zero, you get brown:
The background color, rgb(80,0,0), is brown.
For a heavier brown, some blue can be added:
Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.