This paper proposes a novel approach of wireless controlled, tenable correlated colour temperature (CCT) lighting system with high colour rendering index (CRI) using the concept of colour mixing. Using Grassmann’s colour mixing theory, phosphor coated warm white LED source (CCT 2800 K) is mixed with the blue and green LED light sources to meet the requirement of high CRI and high value of red object identification parameter R9. A detailed mathematical formulation is derived for easy controlling of variable CCT and illuminance and a flowchart of wireless control scheme is incorporated and experimentally validated in this article. As a result, the locus of the blended light source is very close to the Planckian locus on CIE1931 chromaticity diagram with a minimum uv D value of +0.0005. This proposed system provides a very wide range CCT starting from 2800 K to 15000 K with a high CRI value of 94 at CCT 5000 K. Another feature of this blended light source is the true colour identification parameter of red object (R9), which is also increased to 93 at CCT 8000 K. This system has very wide application in industries like textile, food processing etc., in museum, art gallery, and medical application like surgical lighting for its high CRI and R9 value with wide range of CCTs. 1. Figueiro M., Rea, M. Office lighting and personal light exposures in two seasons: Impact on sleep and mood // Lighting Research and Technology, 2014, Vol. 48, #3, pp. 352–364.
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• colour mixing
• light emitting diode (LED)
• open loop system
• variable CCT
• wireless lighting control