Systems Management

I have Organizations set up and currently three are included. What I don't want however are the users split up. We have decided to contain them all in the default Organization. When the users log in, they are presented with a username field and a password field. They also have a drop-down selection for an organization. I do not want my users to have this option. I've looked for a way to remove it and this is all I have found.

 "By enabling the Login Organization Drop-down, the empty 'Organization:' field on the Welcome login page will be replaced with a drop-down of configured organizations. Note, that the organization field or drop-down only appears if more than one organization is configured."

This is what happens if I select the checkbox and enable it. What I would like to do is remove it as an option, or maybe at a minimum change the font color to white so the users don't see it. :-)