Hi
That's odd. I can confirm that it works in popups, both locally and on live environments.
I guess it's a good idea to try to narrow this down.
Do you run the same version of SilverStripe in both environments?
Do you get any errors in Firebug when you try to open a colorpicker on the live server?
Any files missing (look at the "Net" tab in Firebug)?
Does the same issue occur in every browser?