Space Wolf Servitors: Delemma

So last time I posted my Space Wolf Servitors. I think they look really good... except... these two guys.

And it is not that I don't think they look good, its just that if you look at them from above (and I mean how often are you going to do that while you are playing a game?) you can see that they are very black. I was thinking that there was too much black on these minis, and when I showed the minis to my wife she said, "these two need something to break up all the black," and then it cemented in my mind.

Now my first inclination is to maybe do some yellow "hazard lines" but a) I hate to paint yellow, and b) I'm not exactly sure where/how I would paint it on so that it would look good.

Another thought was to maybe make the backpack metal.

I'm just not sure, so for the moment they sit.