If you know enough CSS you can make your brill look like almost anything. However, a good brill should still look like it is part of isBrill. Here are some example customisations that work well.
Doctor Who isBrill.com
The Doctor who brill takes on the hardest of tasks, reimagining the iconic brill sign to fit the topic. While 99% of the time, I would say this is a bad idea, this example just works.

Tea isBrill.com
The tea brill takes a more subtle approach to customisation by quietly reworking some of the colours and text sizes. What in most cases is a weak page header has become a thematically coloured strong header.

Steampunk isBrill.com
The steampunk brill makes the most of background colour to really bring out the subtle brill-roll image but replaces the Brill-i-tude with a steampunk reimagining. With just a few tactical colour changes, this brill manages to feel very different without really changing very much.
