The calibratable Light Colour/Brightness Sensor for the ISYGLT system can be used as an outdoor or indoor light sensor. Many different curves and value queries are available to use the sensor for a wide range of applications. A special application is the regulation of light exactly to the desired light colour, e.g. in offices, schools, industry (e.g. control room) or museums. Due to the direct measurement, daylight is also included. Another interesting application for biologically effective lighting control is the measurement of outside light and the transfer of the exact value to the indoor.