If I recall correctly: The blue value of any light must not be zero.
To be sure always use 1 as lowest setting for each color component.
Example:
For a red color:
rgb(255,1,1)

About your screenshots:
Interesting for a start and a beginner.
But there is definatly room for improvements.

Hint: Find a game that suits the style you are after, run it and just take a look at the level design.
Make notes or even some sketchs and pay attention to details like: how to they embed a door into the wall, how is the transition from floor<->wall and wall<->ceiling .. what other stuff is in there etc.
You should also consider what you design as blocks (wed) and what you could add as models. (cables and all the fine detailed stuff should be models)

edit:
You should also always keep in mind what function the room has and what might be needed in the real world.
But don't just try to make everything "real" .. as a game developer you mostly need to make a compromise between "real" and "gamer friendly".

If you have the chance: pick up the HL2 episode one (and two) and play it with the comment marks switched on, there are some nice hints and tricks where even indies can learn from.