Bay Window – Sunlight (6000° Kelvin = Blue)
Light Fixture on Ceiling – Bulbs (3500° Kelvin = Yellow-Orange)
Dark Corners – Shadows (7500° Kelvin = Dark Blue)

So with all of these conflicting Kelvin temperatures, how could anyone shoot an accurately colored photo?

In most residential homes, you can simplify your options to either daylight balanced or tungsten balanced.  First, you must determine your primary light source, and then attempt to match the rest of the room to it.  For instance, if a large bay window illuminates the room, then opt for daylight.  If there are no windows, and the primary light source is a ceiling fixture, opt for tungsten. 

When shooting daylight interiors you may choose to work with the natural ambiance, and turn your flash off.  Ensure that your white balance is set to daylight, and use a tripod if the shutter speed is too slow to hold it still by hand.  If you need more light, use your flash (which is also daylight balanced).  More experienced photographers may choose to use a lighting system where the flash is not physically connected to the camera.  Most external flashes today can communicate with the camera or another flash via infrared signals so there is no need to string cables around the room.  You may also choose to turn off any tungsten-balanced interior lights if they affect the coloration of the photo.

When shooting tungsten lit interiors, you might again choose to work with the natural ambiance, and turn your flash off.  Just ensure your white balance is set to tungsten.  Because tungsten light is a lower Kelvin temperature than daylight, you will likely need a tripod if you want to shoot at a lower ISO.  If you need more light, you will have to use your flash.  Yes, you can convert a flash from daylight to tungsten. 

To convert your flash you will need:

1)      “Gel/Filter samples booklet” – available at all production/studio lighting stores, and many photography shops.  They are often free and rarely priced over $5. 
2)      Tape
3)      Sturdy Paper

First, loop a 1-inch wide strip of paper around your flash and tape it down.  Cut out the “CTO +.3ND” filter (Color Temperature Orange +.3 Neutral Density Filter) from the sample booklet.  This will be Lee Filter #207 (alternate brands: Cinegel #3405, E-Colour #207).  Lay it over the bulb of the flash and tape it down onto the paper.  You should end up with a scoop-like filter that can be slipped over your flash (see sample before and after).  Now you have a tungsten-balanced flash!