To change the colour (CCT) please turn off the main switch and on with in 5 second. colour switching cycle 6500K-3000K-4000K. Default CCT will be 6500K. CCT/Colour can be changed by On/Off switch. energy efficient :saves 60% more energy over conventional DL. long life- maintenance free up to 30000hrs. Wide voltage operation -100V to 300V High lumen efficacy-90Lm/W. (Cool white ,Netural white,Warm white)