I have a lot of LEGO Sets and have noticed that some of them have yellow hands and some have a dark grey colour hands. Is this because some are of old design and some are of new design? Most old ones have yellow hands, though?

This minifig has yellow hands:

![](https://vignette2.wikia.nocookie.net/lego/images/e/e8/60042-officer.jpg/revision/latest?cb=20131211210007)

And this one has grey:

![](http://vignette1.wikia.nocookie.net/lego/images/3/33/Cty027a.JPEG/revision/latest?cb=20101207021037)