"Bashish" took up where the long extinct "Bash Prompt Package" fell away, packaging prompts and terminal appearance as themes, allowing easy changes without knowing anything about your terminal, fonts, or shell programming. And if you think my prompts are garish, you'll be rethinking once you've seen Bashish's examples. Their software is available at http://bashish.sourceforge.net/ : the project seems to have stalled in late 2006.
They recommend the use of the "rxvt-unicode" terminal emulator, compiled with the "--with-frills" option. It will work with other terms to a lesser extent. They have several fonts they recommend: see their documentation.
Their documentation has an interesting section that I will quote verbatim:
Giles Orr has written an extensive HOWTO on prompting in bash, see the Bash Prompt HOWTO. It has quite a few ideas and a general description of prompting, however, there are a few things that differ the Bash Prompt HOWTO and the way prompts are written in Bashish:
I've not tried to install or use Bashish in several years: it looks like a good product, but conflicts with my way of handling prompts.