Here's a link to the sunset room PSD. I have organized groups so you can take a look at how I created the lighting from the base room.
Using local colours is essential when you want to create various lighting situations. Local colour is the colour of your object without the influence of different lighting, i.e. how the object would look under regular daylight. With this base color, you can create any lighting on top of it. I'd like to make a tutorial someday about this!