[neilk]

It's so that security guards and others can enforce area bans just by looking at your badge. For instance, some gatherings might be open only to white badges, some to white + green, the shuttle probably isn't available to yellow badges, etc.

[sundae79]

Why do you need security guards to enforce when your badge is electronic(RFID). You swipe your badge everywhere you enter(including cafes inside buildings for which you swipe your badge to enter), especially in a company that is tech oriented. I dont think anyone with a white badge enter without swiping.

[jlees]

there are areas (eg. meetings in cafes) where you don't have to swipe through a security door to get in. these are policed by physical security.