Info. required about a Citizen

[Beetle75]

I am trying to find out what year this Citizen pictured below wasade. The model number on the back reads:
GN-4W-S
The serial number starts with 3O. I presume this means October 1973/1983/1993. (Similar to Seiko)
Can anyone help in identifying what year. The colours on the dial changes colour as the second hand moves around.

http://i1289.photobucket.com/albums/...pslebt9jtq.jpg

[fakeyou]

Haven't got a chance to wear citizen watch. Any popular models to recommend

[Beetle75]

Really not an expert but I do like the Bullheads from the 70's.