LED lights and lighting solutions have just recently developed to a quality of lighting which is suitable for replacing household light bulbs. LED lights have been around always, and have been part of our lives for a longer time than we realize. The technology was first invented at the beginning of the 20th century, however its significance, and its option of practical use have only been recognized years later.

The first LED lights developed were not suitable for lighting purposes, but were perfect for signalling (in electric appliances for instance – they are still in use), and has been in use for half a century now in watches, television sets or Hi Fi system.

Those who were aware of these applications will not find it strange to hear that, unlike other forms of lighting, LEDs existed in coloured forms at first. While incandescent or fluorescent forms of lighting primarily exist as white light -and colours are usually only added with coloured glass covers, LED lights are based on various semi-conducting substances emitting light when current runs through them. Depending on the substance, the colour of the light emitted changes. The first red LED was introduced in the 1960’s, and other colours were developed during the 70s, like green, orange and yellow.

It wasn’t until the introduction of the blue LED when creating white light LEDs became available. Blue LED lighting was the most difficult to create, since the human eye detects it the most difficultly, so the brightness of blue light had to be twice as intensive than of other colours.

Today,there are several methods of creating white light with LEDs. One of these is with the RGB technology. RGB LEDs contain three light-emitting diodes combined into one single LED. By simply releasing all three of the diodes, the three coloured lights melt into one white light.

Another way white light is created is with a phosphor coating on most often blue, or sometimes yellow LEDs. The blue LED with a phosphor cover can emit a bright, bluish white colour temperature, while the yellow one emits warm white colour temperature.

Colour temperature is best described by the chart below, where you can check out the whole range of colour temperatures. Higher Kelvin rates are called bright white colours (over 5000K), the 3000 Kelvin rated colours are warm-white, and the ones around 4000K are usually called natural or pure white.