Before I entered real estate I was an electrical contractor and spent a portion of that career working specifically with lighting. In fact, I was an award winning contractor through Salt River Project, winning two awards for my work in the lighting field.
There are two keys to proper lighting, Kelvin temperature and Lumen Output. The Kelvin temperature is the overall color of the light while lumen output represents the true light output. Combined both work together to give the appearance of light and influence color and how it looks.
When we speak of color temperature think of it as make up. The correct color temperature in the right place can make all the difference in appearance. The lower the temperature the more red the light will appear as the higher the temperature the more blue the light will appear. Light easily affects any objects appearance, for example in a meat case we generally use a lamp in the 2000 color range while at a car lot we want something in the 8-10000 range. A bright blue will make the shiny car colors "pop" while a dark red makes meat look more appetizing.
Traditional light bulbs (incandescent) tend to be in the 2500 color range, thus when we purchase a newer LED or CFL type lamp we should be looking in that color range which is listed on the box. In a darker room painted a red base color I would actually choose a lower Kelvin rating where in a more yellow room I would tend to stay closer to the traditional 2500 range.
To brighten a room try a lamp with a greater lumen output rather than a "hotter" kelvin range. Remember the bluer the light the more it will wash traditional pigmented colors and the "cooler" the range the more red things will appear. When thinking of lumen output, a traditional 60 watt incandescent lamp puts out about 800 lumen's. Therefore if we really wanted to brighten up a off white room, I would choose a 1600 lumen lamp in a 3000 temperature (closer to photography light).