Other times, if they are in difficult areas and the flow is good and not badly discolored or washing sediment into the basins, we will only do the main trunk line but leave the subsidiary lines.

Some individuals are more prone to develop Keloid scarring which results in a raised and discolored scar.

Obviously I got some dry wall damage, some bubbling, cracks, and discoloring.  

I have some moisture (I think from the window AC unit) that has discolored 6 or 7 pieces of the floor right next to the wall and I'm turning the unit over and need to figure out a solution.

For example you said "remove all existing toilets" which is great a perfectly clear doesn't leave anything that will be a question of your interpretation vs the GC's.On the other hand "removal of damaged sheetrock" may possibly lead to (contrived) you believe it is water damaged and should be removed, GC believes it is just discolored and only needs fresh paint.That's just an example and maybe the easiest way to attack that kind of thing without having to spend a massive amount of time and energy would be to have a clause about the "acceptable condItion" which is your discretion not the GC or maybe a short list of definitions that is standard across all your SOWs that define acceptable condition....If you have RocketLawyer or know a great contracts guy I am sure they could help fairly quickly.Again, no expert but that is what came to mind, I will be interested to see the other replies.

Banks use the term discoloration because they don't want to say mold.

The kicker was that Fannie Mae and Freddie inspectors along with the banks referred to moldy areas in homes as "discoloration" on the inspection forms.

But after we had painted the interior and of course it rained a few days later, I noticed a slight discoloration. 

Dale Shin ,  lets see,  replaced all windows, due to discoloration and damage,  the pic of the two windows the one on the right was a patio door,  the garage was 3/4 enclosed and used for dogs, ( found 9 portable kennels in the attic). and it smelled like it too. 

There is some discoloration due to heat cycling (rainbow effect) but otherwise they are perfect.The multi ply is important for longevity.