Recently I was involved in a lot of trouble shooting a complex network flow. Close to 8 iftops keep running on my extended monitors and at time it becomes difficult to differentiate the download and upload bandwidth with one look. So I thought let me top this excellent bandwidth monitor tool from Paul Warren and Chris Lightfoot with colors. here is how it looks.
The code is available in github. If you are using ubuntu, you can directly install iftop colour version from this PPA. Basically I have patched on the latest code avaialble for ubuntu 13.10 (Saucy). David Heidelberger has ported it to Gentoo
[Update: 24May2014] updated ppa for ubuntu 14.04 – Trusty Tahr . Git has the latest code.