I wish the Code panel would make up their mind on what that #8 wire is called. The '02 calls it a grounding conductor and so the color code would kick in but, the '05 calls it a bonding conductor and the color code would not apply???IMHO.
The NEC is full of confusion...the old 'grounding or bonding' issue abounds. As a "simple mans' rule,' when I get confused I ask myself "is this wire for lightning protection?" If so, then it's a 'ground.' If not, it's a 'bond."
Using this understanding, let's consider the wire from the panel to the water pipe. In an old house, where there is no ground rod, this is a 'ground wire' or GEC. In a new house, this wire is there to clear any fault current to the plumbing- so it's a bond, not a ground.
Probably over-simple, but it does help me keep focused.
Shortcircuit has it. There was an error in the code when they called the #8 in the pipe to the forming shell a grounding conductor and it was fixed in the 2005 code. There were 4 proposals that all said essentially the same thing (17-93, 4, 5 & 6)