What Les said doesn't seem to make much sense, but it's actually true. Instead of thinking about what colors should be present, instead try to think about creating shadow, and more importantly, WHY night looks the way it does.
First, establish your motivating sources. You mention a "candle on a table" - are there any other practicals suggested or present in the set? Maybe a wall
sconce or two? A fireplace? Start by plotting out soft areas of warm, amber light around these practicals to make it appear that the actors are being lit by the actual source and not by
stage lights. For the fireplace, consider using two or three different units with slightly different colors to give a realistic fire
effect - there was a good thread here a few days ago about making a believable fireplace, and a search should turn up even more thread on the subject.
Once you've got that, work with your windows and doors - in an interior room, what makes night different from day? The only difference is the light streaming in through windows, doors, cracks in the walls, skylights, and so on. So what color is "night"? We tend to associate night with deep blues, and without getting into a discussion about color perception and human
vision, this is essentially true. But night isn't always the same color everywhere you go. The blue you'd see standing on the shore of a large lake would be very different from the blue you'd see standing in the middle of a dense forest. While you don't necessarily need to specifically establish exactly what natural feature lies outside each window and door, you should be aware of this difference, and use slightly different shades of blue to provide more depth and realism. And what about the biggest motivating source of the night sky - the moon? If appropriate, maybe designate the moon as being "off
stage right" or something, and add a
unit in a lighter shade of blue to simulate the
effect of moonlight streaming through the window. And don't forget about gobos! Natural light is rarely the
flat, evenly-spread beams that our lighting instruments produce. Experiment with some gobos streaming in through windows, maybe to simulate light shining through trees, or to just show a hint of
reflection off a body of water, or anything else.
Now after you've gone through and thought about all this, then you need to adapt your design to work in a
theatre setting. Because the need for visibility generally overrides the need for realism in the
theatre, we are often forced to add more light to the
stage than would be seen in an actual setting. Gillette suggests that a night scene can be done effectively by using a deeper blue
wash of color from the front to fill in any remaining shadows. Gillette's example uses R79, although you should choose a color that works with your show, set, and costumes. Keeping your "warm" lights (motivated sources from candles, sconces, fireplace,
etc.) at a lower
intensity will both reduce the amount of light hitting the
stage as well as increase the
amber drift, giving you a much more candle-like feel.
Tonight after it gets dark, find a room in your
house with a couple windows and turn off any source of artificial light - including lamps, clocks, oven timers, whatever you may have in the room. Then really look and think about the light in the room. Where is it coming from? What color does it appear to be? Is it hard, sharp light, or is it very soft and diffused light? Then, light a single candle and place it in the middle of the room. Now, reanalyze the lighting and ask yourself the same questions. How does the addition of the candle change the existing lighting? Remember, you havent actually removed any of the light that was there before, you've just added another layer. By starting with the smallest layers in your design and working upward, you will be able to create a very effective night scene.
I hope this helped somewhat, let me know if any part of it doesnt make sense. A first lighting design is always a great experience, no matter how it turns out. Good luck, and have fun!