Both,they're coloured surface mount LEDs.Not very difficult to change as long as you make a note of their polarity beore cutting them off with a pair of small wire cutters.Then unsolder the remains one side at a time,clean the excess solder off and solder the new one in place as quickly as possible.Chris,
Are they white surface mount l.e.d.'s or actually coloured ones?
They do run off SLIGHTLY different voltages Graeme,red normally quite low at under 3 volts and blue up to 4 volts in some cases.It might be possible to choose some at the lower end their range (some are only just over 3 volts) so you probably wouldn't see too much of a difference.They aren't old fashioned resistor driven though,there's a dedicated chip that controls all the warning lights and illumination so not very easy to change the voltage.Do you need to change the resistor as well - I thought say a red SMD or a blue SMD would run with a different resistance as well??