Car Battery going on its third YEar.. should i replace?

HI all, to my surprise, my car's battery (MEGA FORCE brand) will be going on its third year in a few weeks. Actually THis is the first time i've had a battery that has lasted more than 2 years. I've checked on the "color gauge", it still has a green color - meaning good (though not as bright when it was new). I don't want to be in a situation where the car wouldnt start in an emergency, etc. Would you suggest to have the battery immediately replaced? or re-charged or just wait till it gives symptoms of failing? Car is Civic 99 EK.

thank you and happy holidays!