You may see so many variations, because some artists (not all, but some) have a philosophy that they want to leave a mark on character's look, so they change something to make it "theirs." The old days of keeping everything "on-model" aren't as prevalent as They were. That's both good and bad.
Well again that's how I would go about making thing's easy to identify, color code then so it's bot confusing. But the problem is that many artist subscribe to the same basic all Black with white eyes balls look as shown in the image I posted above. Sometimes that can work, if you use shading to give the finer details, something David Marquez pulls off (and then when he activated the solar flare with Tony we saw the finer details of how intricate the habit is when it lit up) the it's fine.
But Travel Foreman's version generally becomes the standard and it's a problem because it often times comes off as lazy and a lack of care to Tchallas detail. Artists have no issue with Spider-Mans costume But can't be bothered to give Tchalla more details.
That's why I respect artists like Acuna, Marquez and Rocafort so much for their attention to his appearance
Yeah, Ultimates' artist just wasn't a good artist at all. Lots of substandard art in that book.
I actually don't mind what I see as Foreman's personal take on T'Challa's habit as the "ninja" interpretation [ "isiyoonekana shujaa"..."invisible hero" ]; I remember that one of the well done cartoons/anime featuring T'Challa with The Avengers ALSO centered on that ninja-like approach. In fact, the stealthy, acrobatic, speedy, hyper-agile, hunter-tracker, deeply cunning, instinct enhancing intellect part of T'Challa's character imo has suffered greatly due to the emphasis on his tremendous megagenius, prep, man of mystery character traits. I would bring these facets of T'Challa's character back with a vengeance in every issue I wrote, and you see it popping up and combining with his other characteristics in my fanfic...
...but again, imo the primary approach is to present all of this as part of T'Challa's comprehensive whole. Imo only special issues or special arcs should emphasize particular traits of T'Challa's, but the general thrust should be how T'Challa takes down, overwhelms, bewilders, and commands respect mixed with a healthy fear from most of his friends and all of his enemies via a jaunt through T'Challa's persistent pantherine senses, instinct, cunning, speed, agility, silence, stealth, tech, Ka-Ba-Akh, multiskill and multidisciplinary megagenius on consistent display as the premier polyglot that he is. All wrapped in his primary "man of mystery", deceptive, misdirection, Emperor King personality.
I think that both Blue Marvel and Captain america would take issue with T'Challa being more oriented toward killing his opponents than either and both of them are. However, this facet of T'Challa's is what would stand him in good stead with characters like Wolverine, Bishop, Psylocke, Elektra, Punsiher, Moon Knight, Tigra, Mockingbird, The Super Soldier, The Winter Soldier, Silver Sable, Echo, Sabertooth, X-23 and The Black Widow... thus making him a very sensible addition to team ups with them/employing them individually or collectively, as he is both cosmic AND more in tune with their "closer to street level" heroics and missions more than literally any other A-List hero.