A lighting fixture (300, 2010, 5000) adapted to generate white light, said fixture comprising: a plurality of component illumination sources (320, 5007), said plurality including component illumination sources arranged to produce electromagnetic radiation of at least two different spectrums (1201, 1301); and a mounting holding said plurality, said mounting designed to allow said spectrums of said plurality to mix and form a resulting spectrum (2201, 2203) that is continuous within the photopic response of the human eye and/or continuous in the region from 400 nm to 700 nm; wherein said plurality of component illumination sources consists of only LEDs, the LEDs including a first white LED, including a phosphor, to produce a first spectrum of the at least two different spectrums, and a second white LED, including a phosphor, to produce a second spectrum of the at least two different spectrums; the lighting fixture further comprises a processor (316, 2020) responsive to data from an external device and configured to independently control the first white LED and the second white LED based on the data such that an intensity of the first white LED and the second white LED may be varied thereby to vary the color temperature of the resulting spectrum within a preselected range of color temperatures; and the lighting fixture being adapted to be connected to a data network and being provided with a data connection of the data network over which data from the external device is received by the processor (316, 2020) of the lighting fixture, the received data being control data for controlling the plurality of component illumination sources (320, 5007). a plurality of component illumination sources (320, 5007), said plurality including component illumination sources arranged to produce electromagnetic radiation of at least two different spectrums (1201, 1301); and a mounting holding said plurality, said mounting designed to allow said spectrums of said plurality to mix and form a resulting spectrum (2201, 2203) that is continuous within the photopic response of the human eye and/or continuous in the region from 400 nm to 700 nm; wherein said plurality of component illumination sources consists of only LEDs, the LEDs including a first white LED, including a phosphor, to produce a first spectrum of the at least two different spectrums, and a second white LED, including a phosphor, to produce a second spectrum of the at least two different spectrums; the lighting fixture further comprises a processor (316, 2020) responsive to data from an external device and configured to independently control the first white LED and the second white LED based on the data such that an intensity of the first white LED and the second white LED may be varied thereby to vary the color temperature of the resulting spectrum within a preselected range of color temperatures; and the lighting fixture being adapted to be connected to a data network and being provided with a data connection of the data network over which data from the external device is received by the processor (316, 2020) of the lighting fixture, the received data being control data for controlling the plurality of component illumination sources (320, 5007).