Qlikview uses themes. On the layout tab of the document and object settings, there is a theme maker button and apply theme button. Check out the manual for themes and search this forum, as I am sure there are some postings on this topic.
You should have some themes installed with Qlikview (I forget the location), and you can create your own themes easily.
Theme Maker starts a theme builder wizard. Basically, to create a theme, you create objects and apply all the necessary fonts, colours, styles etc and then use the objects as the source from which the theme will be built. You can also define themes that apply only one property or any collection of properties relevant to that object type. The easiest way to learn is to dive in and experiment.
On the User settings Design tab you can specify and default theme which will be used in new documents and objects.
Hope that helps