well when i dream and get lucid its never really a bright dream and i loose conciousness within like 10 seconds why
because your mind is pre conditioned to that end result.
Next time you go to sleep, imagine the lucid dream you want to have, how you want to see and perceive, how you want to feel, and know that it will be that way.
Dont get discouraged if it still like that for a few more times, your mind may time some time to adjust, nonetheless, if you maintain this state of mind, you’re gonna find yourself enjoying those lucid dreams pretty soon. 
hope this helps
Actually, whenever I get lucid, I have a hard time seeing… I’m guessing that’s what you mean by “Not bright”, so if you become lucid, before anything else, try to stabilize the dream somehow (there are methods to do this somewhere in the knowledge base)… it worked for me the last time I had one. It wasn’t dark like it usually was…
I hope it helps…