Temperature? Of light bulbs? What does that mean?

It has nothing to do with how hot a light bulb gets, but relates to the color warmth of the light. Most light is not pure white, but has a bit of a tint to it.  There are many different shades of white and the ones you choose will make an enormous difference when it comes to lighting your home. Choosing the wrong light bulbs can destroy your plan for a warm inviting living space.

In stores you may see descriptions like, warm white, cool white, clean white, soft white. These are vague terms and are not really helpful when it comes to selecting light bulbs. What you need to know is the Correlated Color Temperature of the bulb you are buying.


It sounds way more complicated than it is.  On all Energy Star energy saving lamps, you will see a number printed in the thousands followed by the letter K or the word Kelvin. A Kelvin is simply a unit of temperature.

The old incandescent light bulbs were in the CCT range of 2700K to 2900K. This is a warm white light with a touch of yellow. It is flattering and easy on the eye. When the new energy efficient alternatives first came on the market, many people were reluctant to change because the new light wasn’t as appealing. It has greatly improved since then. The range available today goes from 2700K all the way up to 6000K, which a cold, very blue light.


The lower number, the warmer or more yellow the light.

The higher the number, the more cool looking or blue the light.

A candle flame has an index of 1800K. A CCT number of around 3500K gives the whitest light. If you want to create a cozy atmosphere in a room, select light bulbs with a CCT of around 2700K TO 3000K for a softer, warmer light.