I don’t really blame Lego because they would need to include black and white pigment into their resources to colour the pieces, although it’s still pretty ridiculous. I have a feeling grey is either their cheapest colour, or it’s the natural colour that the plastic is, when the pieces have been finished being manufactured
I think grey worked well with the Toa Metru. It added to the industrial Metropolis feel to the series.
2008 though, that was way too much. I guess we should be grateful they threw in some gun metal to mix it up xD.
Since nearly a tub full of useful pieces are gray, it makes it even harder to have a consistent color scheme for MOCist, which could be seen as a challenge for the creator or a pain in the Berix to get right.
I think the only pieces that should be grey in the 2008 sets should be the parts that were grey in the Toa Metru sets. So basically the biceps, triceps, quads, hamstrings, weapons and the little bits and pieces like the hands and the very small pieces. The Phantoka and Mistika would have looked so much better if they were like that. 2008 Tahu suffered the most from the grey overload.
The way I see it, grey was meant to represent their mechanical parts of their bodies, wheras the coloured parts were either armor or part of their natural muscle/tissue.