Forward voltage: 1.8 - 3.4V DC
Luminous intensity: 500-20000 mcd
Forward Current : 18-20mA
Forward Voltage : 3.0-3.2V (Blue, White, Green,Warm White) ; 2.0-2.2V (Red, Yellow)
so would 2x the above be ok? as the odd 4 has 2 green ones in, there is no resistors on the above leds really...