An LED unit includes an LED and an electrochromic element mounted on the LED. The LED includes a base, a light emitting die mounted on the base, a pair of leads electrically connected to the die and an encapsulant sealing the die. The encapsulant has a first area and a second area around the first area. The first area contains yellow phosphor therein, and the second area contains red phosphor therein. The electrochromic element has an opening through which the first area of the encapsulant is exposed. The second area of the encapsulant is covered by the electrochromic element. The electrochromic element can change its color when being electrified, thereby changing the color temperature of the light output from the LED unit.