I have some of the Anthracite Systainers and they certainly do attract lots of saw dust very easily. But as someone else said, this is removed very easily unlike other dark marks and stains on the light grey Systainers.
Also, I'm bored of hearing people dig at those who like to keep their systainers/stuff clean. .
Next to producing good work and keeping the clients house clean, I have no doubt that turning up with smart, clean, neat and organised gear helps impress my clients. While that may sound stupid to most people here it really can be the case. My systainers are only used at clients houses, in my workshop they are stored out of the way.