I see nothing that has been changed, even the color is Kirbys, anyone can go look. I put both side by side, so I have no idea what your claiming. Sorry, but I looked at a few pics of this. Anyone can check it out here below:
Sometimes the cover makes you ask a question. On this one it was how do we get across that the Hulk is green while not changing him from the original Grey that he was for the couple of issues. So making Banner glow green seemed to work and then setting up the red BG seemed to flow from there and then winged it as best as I could in the time I had to get it done.
It was a brilliant decision. You were able to capture the two colors of Hulk in a way that works. It reminds me of a recolor done to a classic Jeff Purves HULK cover for the "Visionaries" trade paperback series: [link]
Hulk is still Grey here, but the eerie green lighting is a great way to please fans of both Hulk hues.
Now, your comment of "the time I had to get it done" implied a fast deadline, but from my perspective, it doesn't show. This looks like a labor of love.