Are ultraviolet LEDs used in consumer lights? (xmas lights)
A 'purple' LED may not be what you think it is. The human eye cannot distinguish between 'true' purple or violet (visible wavelengths shorter than blue) and a mixture of red and blue light.
Most 'white' LEDs use a blue emitter with a phosphor to convert some of the light to longer wavelengths. To create a purple LED the phosphor just needs to peak in the red part of the band rather than yellow.
Example spectra of Purple LED globe:-