"White tea" does not refer to black tea with milk, but rather to a specific form of tea in which the leaves and buds are simply steamed and dried. In this sense, white tea represents the least processed form of tea, since green, oolong and black teas undergo withering before various degrees of oxidation. White tea also contains a higher proportion of buds, which are covered with fine 'silvery' hairs that impart a light white/grey color to the tea. White tea brews to a pale yellow/light red color, and has a slightly sweet flavor with no 'grassy' undertones sometimes associated with green tea. Researchers at the LPI tested four types of white tea for their ability to inhibit mutations in bacteria, and subsequently examined the protective properties in a rat colon cancer model. In the former studies using bacteria, white teas were generally more effective than green tea in inhibiting mutagenicity (mutagenicity is a result of unrepaired/misrepaired DNA damage and an early step in the process leading to cancer). White teas contained many of the expected polyphenols, some of which were present at higher concentrations than in green tea brewed under the same conditions. Other constituents, such as caffeine, also were present at higher levels in white tea.