A blue rinse is a dilute hair dye used to reduce the yellowed (or translucent, showing scalp colour) appearance of greying hair on older women. The ability to see blue decreases with age due to the development of cataracts, so an older woman perceives her uncoloured hair to have a yellow-tinge, and the blue rinse brings the colour back to a perceived normal colour in their eyes.[original research?] In a manner similar to laundry bluing, the blue rinse can make yellow-white hair appear blue-white, but an inexpertly applied blue rinse will leave a distinctly unnatural tinge behind.
The "blue rinse" may also stem[original research?] from a popular trend in the 1930s, popularizsed by film star Jean Harlow, for young women to dye their hair with peroxide and then follow with a rinse of methylene blue to take out the yellow, creating the desired platinum white effect.
The phrase entered popular culture as a term for elderly women, the blue rinse brigade. An alternative term is "blue hair." It has declined in popularity with the increasing popularity of home dyeing, the reduced prevalence of smoking (which yellows the hair), the increased ubiquity of cataract surgery, and with society's more relaxed attitude to ageing.[original research?]