There are number of thing I do not like about default Tabstrip Component look:
1) Tabs headers are not standing out from tab panel content;
2) There is padding between tab border and tab content;
3) Tab panel background color does not fit into overall design;
4) Tab panel border is visible outlining empty space between tab panel border and tab panel content.
All above can be easily fixed using Custom CSS.
Here is how Tabstrip Component is displayed by default:
After applying Custom CSS the same application looks way better:
All it takes is upload following CSS Enhanced Tabstrip.css file into Business Objects Server
and assign it application properties