The colour of light is expressed in Kelvin and in point of fact, we are talking about colour temperature.
What tangible examples can be provided for this colour temperature? At a higher colour temperature, the light becomes a deeper blue (cooler), whereas the light becomes more yellow (warmer) at a lower colour temperature.
Please refer to some examples below.
| Candle light | 1200K |
| Sunrise | 2000K |
| Sunrise after 1 hour | 3500K |
| Day light | 5000K |
| Mid-day sun | 5700K |
| Neutral white light | 6500K |
The colour temperature has a great influence on the atmosphere in spaces. For example: warm light makes you quieter, whereas blue light increases your concentration.
Please refer to this overview of colour temperatures that Calex provides:
| Flame | 2200K |
| Extra warm white | 2100-2500K |
| Warm white | 2500-3000K |
| Cool white | 4000K |
| Day light | 6500K |