Preserve ls colouring after grep'ing

If I do

$ ls -l --color=always

I get a list of files inside the directory with some nice colouring for different file types etc..

Now, I want to be able to pipe the coloured output of ls through grep to filter out some files I don't need. The key is that I still want to preserve the colouring after the grep filter.

$ ls -l --color=always | grep -E some_regex

^ I lose the colouring after grep

EDIT: I'm using headless-server Ubuntu 8.10, Bash 3.2.39, pretty much a stock install with no fancy configs