You need to talk to who is in charge about culture!
There is a such thing as too casual, especially when you are in a corporate environment (ie bank or financial) and if you are in front of people, how you dress speaks volumes. Sure there are people who prefer :'extra casual', but before we criticize them, we must consider their environment and culture. IT Pros must always be comfortable and wear clothes that are easy to take care of. I have been in both and Khakis is the way for me.