Hi,
When you say "the colour is off" do you mean that it is showing unusual colouring or that it is in one colour only?
If there is 'colour' what colours if any are you seeing? It looks like it has a CRT screen therefore it would have 3 electron guns to produce the colour. You need all three, Red, Blue, Green working to get White. Here is a video which describes how a colour CRT monitor works.
https://www.youtube.com/watch?v=Gnl1vuwj...
Unusual colouring is usually caused by one the the three colours (RGB) not working. What you need to determine is which colour is 'missing' and then find out if the problem is in the CRT monitor section i.e 'guns' not working or in the control pcb supplying the monitor section with the colour signal information
Be aware if it is a CRT monitor that there are very high voltages present. You can get a shock (possibly lethal) from a CRT tube, long after the power has been disconnected. It is like a huge capacitor. If you don't know what you are doing get expert help.
Here is a link to some sort of service manual for a Final Fight Arcade game. I don't know if it is the exact one for your model but it may have some information (including Contact info - if they still exist) that may be of some help to you.
http://www.gamesdatabase.org//Media/SYST...