Canon Rebel T2i EOS 550D Instruction Manual page 76

A Selecting a Picture StyleN
S Neutral
This Picture Style is for users who prefer to process images with
their computer. For natural colors and subdued images.
U Faithful
This Picture Style is for users who prefer to process images with
their computer. When the subject is captured under a color
temperature of 5200K, the color is adjusted colorimetrically to match
the subject's color. The image is dull and subdued.
V Monochrome (C: Monochrome image)
Creates black-and-white images.
Other than with 1, the black-and-white image cannot be reverted to
color. If you want to later shoot pictures in color, make sure the
[Monochrome] setting has been canceled. When [Monochrome] is
selected, <0> will appear in the viewfinder.
W User Def. 1-3
You can register a basic style such as [Portrait], [Landscape], a
Picture Style file, etc., and adjust it as desired (p.91). Any User
Defined Picture Style which has not been set will have the same
settings as the Standard Picture Style.
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