Hi there. I don't have DarkLights but the issue is with the way it is set up to load help files. So when your DarkLights installed, it will have placed a .ini file in your keywords file to tell the IDE which words need syntax highlighting. If your DarkLights commands are showing in blue as they should, then the file is OK. In that case, you need to find the file (only do this if you really care because it will take a while). You'll find the file under your DarkBASIC Pro install directory Editor\Keywords\ . In that folder, you need to the find the file that will presumably be called something like DarkLights.ini. Open it up in a text editor. The structure is:
COMMAND NAME HERE=file\path\command.htm=parameters here
So an example would be:
CREATE ANIMATED SPRITE=commands\sprite\CREATE ANIMATED SPRITE.htm=Sprite Number, Filename, Across, Down, Image Number
The address of the help file between the two = signs is what tells the IDE what help file to load. The address is relative to the Help file under your DBPro install. So you may need to move the documentation into the Help folder if it's not already there or you may need to correct the addresses if they are wrong. If you really have to go through them all because they're all wrong, I suggest writing a little DBP program to automate the process for you.
Hope that helps. Do say if that didn't make any sense.