[Typo3] Common template with user customizations

[Jane Larsen]

I wish to make a common template for some subtrees in a Typo3 site
(its for a project with som "sub pages").

I would like to make the template so that the editors of the
individual sub tree can have som customized coloring (maybe 5-6
predefined schemas) and they should have the option to have their own
"banner" or som other sepcific graphic element (logo/name)

Is this possible without making problems for myself?

//Jane Larsen