Various arrangements for using multiple wavelengths of electromagnetic radiation to detect smoke by a smoke detector are present. Multiple modes of the smoke detector may be used in which a first wavelength of electromagnetic radiation is emitted into a smoke chamber while a second electromagnetic radiation emitter is disabled, a period of time is waited, and a second wavelength of electromagnetic radiation is emitted into the smoke chamber while the first emitter is disabled. Depending on the mode of the smoke detector, the period of wait time may be varied.