Very green...

Green is the color which is used for most of the piping in the main (sea)coolingwatersystem.
This picture was taken from just under the generator busbars, looking down into the basement of unit EC5
You can see the two coolingwaterpipes, coming in from the upper side of the picture. The two round things are manholecovers, through which one can access the sytem. The coolingwaterpipes have a diameter of appr. 2 meters.
Just below (after) the manholes are the two debrisfilters, each has a rotating screen and a (grey) discharge pipe which leads the debris (mussels, barnacles and so on) round the condenser and deposits it in the seacoolingwater outlet.

Here in LARGE...

Here is another view.