iTerm is much better than the standard OSX terminal client, not least because it has compatiablity with xterm256-color terminal emulation. xterm256-color emulation will give your terminal access to 256 colours instead of the usual 16. Much better, not just for looking pretty, but for distinguishing between different types of data in an editor like VIM or even in Cucumber output (see picture above). It’s also free.
Once installed, you will have to go in to the preferences and set your ‘Report Terminal Type’ to be ‘xterm256-color’. Then things should be more colourful. Then install a 256 color compatible theme in VIM to make use of that extra capacity. You can also edit your prompt and use 256 colour escape sequences, if you wish.