Colouring John Byrne - Avengers vs Ultron

I don't think I've posted this one before in my blog, so I though I'd do it now.

I coloured this John Byrne piece featuring Ultron battling the Avengers (Captain America, Thor, Iron Man, Hawkeye, the Scarlet Witch, Yellowjacket, and the winsome Wasp) a little while ago. One tricky thing with it was wanting to keep the interior of this hi-tech lab a fairly neutral colour (to allow the heroes and villains to really pop) while keeping Ultron in a cool grey tone. If Ultron's grey was too muted, it would fall into the background, while if the background was too warm (to separate from Ultron), it would stop looking like another shade of grey and start looking orange or something. I think I straddled that line fairly well here.