The basic T-Zone LED Device uses white LEDs with cover colours. There are three replacement LED plates available for the Device. The plate LEDs use the wavelength, 470nm, 660nm or 880nm. 470nm appears as blue light. LED Device sold separately.
There are studies showing this wavelength helps with skin surface issues to make the skin more attractive. The blue light can be used for up to 15 minutes per day on problem areas.
References
Blue light (470 nm) effectively inhibits bacterial and fungal growth:
http://www.ncbi.nlm.nih.gov/pubmed/23009190
In vitro effect of 470nm LED in keloid fibroblasts:
http://www.scielo.br/scielo.php?pid=S0102-86502011000100006&script=sci_arttext