Most are green when functioning properly. Many have no lights at all. Try depressing the reset and see if the outlet works again. If not there are other things to look for. Often times one GFI outlet feeds multiple more outlets from the "load" connection on the back side of the GFI. If there is something wet, overloading the rating, or something with a fault in any of the outlets multipled off the single GFI it will trip. Disconnect all devices then attempt to reset. If that doesn't work and you possess some electrical skills pull the GFI outlet and disconnect the wires going to the "load" connection (While power is off) Re-energize and attempt to reset the GFI Outlet. If it resets your problem is beyond that outlet in the circuit of what you disconnect. You may not have found all the affected outlets. FYI if you have a 15amp GFI the rule of thumb is you can put more devices on outlets working off or through the GFI that add up to more than 1500 watts. If it is a 20amp GFI a quick rule of thumb is no load over 2000 watts. Space heaters, blow dryers, and hair curlers are often 1800 watts each. One alone and can trip a 15 amp GFI.