Are the hex codes for colors in a jpg the same codes as used in html?
 

Are the hex codes for colors in a jpg the same codes as used in html?

I am trying to search for porn on my sons computer (which I own), using Helix and Autopsy, and the dropper in photoshop tells me the a common skin tone is E2A684, how ever if I create an jpg or even a gif of just E2A684, I can't find the hex string E2 A6 84 anywhere when I open that file in a text editor. Is the hex string for that color different? How can I search for a certain color by opening a file in a hex editor?

This won't work!

Jpeg files are not bitmapped but are saved as a set of mathematical formulae to recreate the picture. It is only once they are displayed on screen that you can search for hex codes.

You're going to have to search for .jpg files, then open them individually.

I'm assuming your son is underaged. When my children reached maturity, I stopped examining the server logs.

Where can I find the mathematical formula?

This company says there software has a skin color detection feature:
http://www.x-ways.net/forensics/index-m.html

There's a jpeg group site somewhere with the specs.

Note that the company you mentioned seems to sell Windows software.