There is no documentation available for [web] style = <template> in hgrc I looked at http://www.selenic.com/mercurial/hgrc.5.html But it doesn't explain about the valid values that can be applied to "styles". It would be better if it is explained with some links to hg's own repository as example.
Fixed by http://selenic.com/repo/hg/rev/b1fc7ea5bb01 Arun Chandrasekaran <visionofarun@gmail.com> help: update help for hgweb template and style (issue4373) (please test the fix)
Fixed by http://selenic.com/repo/hg/rev/85ade05dc5b3 Augie Fackler <raf@durin42.com> help: document that default hgweb style is called paper (issue4373) (please test the fix)
Bulk testing -> fixed