What is meant by light color or color temperature?

The term light color describes the impression, the mood of light. In order to give this subjectively perceived impression a quantitative framework, the color temperature, with the unit Kelvin (K), was created.

In simplified terms, a distinction is made between three color temperature categories

• Warm white 2,000° 3,300° Kelvin
• Neutral white 3,300° 5,000° Kelvin
• Daylight white over 5,000° Kelvin

Depending on the area of application and the mood to be achieved, attention should be paid to the color temperature when selecting the light source:

• Warm white: has a cozy, homely effect; area of application:
  from 2,700° K: living rooms, restaurants, hotels
  from 3,000° K: entrance area, kitchenette, desk, meeting rooms, sales rooms
  
• Neutral white: looks more functional, yet homely; area of application: kitchens, bathrooms, corridors, in offices or sales rooms, doctors' surgeries
• Daylight white: has a technical, cool effect; area of application: mainly in industry, outdoors, but also in garages, for example

To better illustrate the abstract unit Kelvin, here are four examples:

• a candle has a color temperature of approx. 1,500° Kelvin
• an incandescent bulb with 100 watts corresponds to approx. 2,800° Kelvin
• the light of a halogen lamp corresponds to approx. 3,000° Kelvin
• the evening or morning sun has a value of approx. 5,000° Kelvin

Color rendering level (Ra) of different light sources

Colors are rendered most "realistically" in sunlight or incandescent light. LED lamps and halogen lamps come very close to this Ra value. This is important, for example, when illuminating pictures or at the workplace.

Source: wikipedia

Want to replace your old light bulbs?

Here is a comparison table LumenWatt.