The default XWiki Skins

Moved to Available Skins, the skins an instance can use and how a skin is identified.

The usage level for a XWiki Skin

Moved to Skin Levels, the levels a skin can be set at and the order in which they are resolved.

Changing the Skin

Moved to one page per level, listed in the sections below.

How to preview a Skin applied on a page

Moved to Preview a Skin.

Changing the Skin at instance level

Moved to Change the Skin of a Wiki, and to Customize a Skin for the overrides the Customize button opens.

Changing the Skin at space level

Moved to Change the Skin of a Page.

Changing the Skin for a user

Moved to Change the Skin of a User.

More about XWiki Skins

Moved to Flamingo Skin in the Developer documentation, for writing a skin rather than choosing one.