Scientists from the National Tsing Hua University in Hsinchu, Taiwan, designed an OLED that can display color temperatures between 2300K and 8200K - covering the entire range of sunlight during the day. The color temperature is controlled using different voltage.

That's the first time this has been achieved - and no other light source can have that kind of color range. They used fluorescent OLEDs, but plan to switch to phosphorescent, to make it more efficient.