I implemented the Latex dBCode a couple years ago, but the recent translation to PHP evidently introduced a bug that I just discovered. The fetch of the image fails, so the code drops through to provide a link to a remote server, instead of creating a local image that it links to. The problem appears to be that the PHP file_get_contents routine cannot include a backslash in the file string, so I can't fetch a copy to store locally.
I included a link to some LaTeX documentation with the Latex Help, but do you think the WikiBooks doc is better?
The Latex dBCode is working. It has been working, but it was a kluge to get around some unexpected PHP behavior. The new code is cleaner, and it also allows the default equation color to be set through the control panel. At present the equation color is set to white.
To select some other color use the Latex color directive, e.g.: