Neal Adams was greatly displeased by what happened there.  Here's his account (from Comic Book Artist #3, which printed his original version of the cover):

"One of the reasons I offered you guys use of the cover, was that Marvel vignetted these characters, not even using Xavier's face and cutting out the rest." It seems some freelance art director had different thoughts about Neal's submitted piece. Neal was “terribly upset” with the published cover. "There's no worse color for comic books than eggshell blue (the most prominent color on the cover).  Look at the reproduction inside. The way this thing happened was they called me and said, 'We're going to reprint this stuff.' And I said, ‘I'd kinda like to have the black-&-whites to retouch them, we're in the ’90s now. Can I rework the pages just a little bit?' They said, 'We've already started work on it.' I said, 'Okay. How about I art direct the color?' They said,‘ 'Sure, we'll send you over some of these proofs.' I know what that means, so I said, 'Okay, I'll do the cover.' So I did it and they vignetted it, and the rest just disappeared! How much can one sabotage by good intentions?" Holding up the CBA #3 cover proof and the X-Men collection, Neal said, "I submitted this and I got that. How would that make you feel?"

The original piece was a wraparound.  Below is how it was supposed to appear, first in Comic Book Artist and then in a later reprinting of the visionaries volume.  I was not able to find a very good scan of the original wraparound but this gives you the idea...

I remember reading that 'Comic Book Artist" interview, and I recall that trade paperback collection from when I ordered it for my shop back when it came out. As I recall, the interiors were recolored in that particularly garish 1990s style of computer coloring. Yeah, computer coloring can still be overbearing, but man, the earliest computer coloring days in comics by so-called professionals looked every bit as ugly as some of the fan-colored pieces done by computer online these days.

As far as letting Neal retouch the interior art, I'm kind of glad that didn't happen. DC let him retouch the classic "Green Lantern" stories from the 1970s in a trade paperback in the 1990s, and it just smacks too much of the thing George Lucas did with the special editions.

Remember those great Tarzan covers he painted?  Or the few Savage Tales covers he did?  Real beauties. 

Criminal. You have to wonder how could've that possibly happened, if Neal Adams doesn't have enough clout to prevent some "junior freelance art director" from butchering his work like that then who does?

And from reading his account he kinda knew that would happen and did all he could to prevent it, but still. Amazing.

On the other hand, I also agree with this. Hadn't made the connection to the "Image Style", though.

Neal Adams imitating Rob Liefeld, go figure. Life is strange indeed.

Also hard agree. Remaster it, present it in the best possible quality but don't change stuff to "appeal to modern audiences" or whatever. That's what the current stuff is for, let classic editions be, well, classic.

Obviously Neal had the best intentions and they actually botched the coloring real good in this case but this got me thinking about the KILLING JOKE recoloring Bolland did himself and is, IMHO, vastly inferior to the original coloring by John Higgins.

Maybe let people do their jobs? Tricky, I know.

Now you can't even get the original coloring KILLING JOKE, only the Bolland recolored one. It still bugs me (although I have an original version myself, thankfully).

I have those as well. It's Neal Adams doing Batman and one is grateful for whatever one can get but... apart from the bonkers, borderline incoherent story I was especially bugged by the "Batman Grabs a Gun" thing.

Frank Miller got it right in DKR: "This is the weapon of the enemy"

  

As for reworking on the originals, I don't like the notion at all. This isn't about special effects, it's about changing the art, which is a big no-no for me.