LED is known to not waste energy, if you've seen those new flashlights that use LED. a battery can last years in those flashlights because no energy is converted to heat most conventional lights. and thats off a battery you buy at eckerds or something...so don't worry, LED is the way to be
and I don't know what you're saying about the EX model being different...I got a Hornet alarm and its red..my friends Viper alarm is blue..I guess it just depends on the alarm brand