How do you lighten up a small room that is brown from top to bottom?

So try these. Use light furniture and lots of lamps. Or, since your husband won't paint, get some light fabric and hang it in large strips around the room. The fabric can be attached with push pins and changed with your decor.

I say add pops of really bright colors like fuchsia or lemon yellow in toss pillows or throws.

Gee, that's a REALLY tough one; I can't imagine a brown ceiling! All you can do is add touches of color in decor pillows, a throw or two and make sure your lampshades are light in color. Dark lampshades will really darken a room. Do you have any piece of worn furniture that you could paint? I'd suggest painting one item of furniture a creamy white (then distressing it a bit) and also, what color are your curtains? If they are dark, can you replace them with a creamy white? If possible, make sure the curtains rods extend past the (vertical) window frame so you can pull the curtains back throughout the day and let in as much light as possible. I wish you luck!

Hang large mirrors on wall across from windows. Large mirrors facing windows reflect additional light into the room.

What about wallpaper? I've done rooms in navy & black backgrounds then painted window & door facings white as well as ceiling then mirrored wall across from Windows to create a very dramatic effect & beautiful room.

It will also depend on what room this is - if it is NOT the main living area, let the guy have his man cave. If it is the main room or one you use alot I agree with lightening it up with fabric and lighting. If the ceiling could be painted it would help alot, maybe he can reconsider just the ceiling?