The Martian Manhunter himself is often a source of this type of thing, being a stoic but sensitive Warrior Poet who loves eating cookies. More specifically, Choco cookies. Mmmmm.
Not to mention as mentioned above he has a secondary secret identity with a name taken from a Sailor Senshi.
Superman pretty much gets away with his garish primary-colored costume because he's...well...Superman. Insulting him for not having a badass gritty costume like Batman's that would just make you look like an idiot.
That said, the New 52 incarnation of the character has clearly caved on this point. The costume is now armor and has a muted version of his traditional color scheme. Also, no underwear on the outside of the pants.
Played with by Garth Ennis in The Magnificent Kevin, in which the title character finds himself in a pub with some colleagues shortly after joining the British Army. The pub is full of manly men, drinking beer and showing off their tattoos... and then in the corner are a couple of blokes sitting quietly, playing dominoes and drinking lemonade. Kev's mate Tony explains that they're in the SAS.
Kev: I thought they'd be hard as fuckin' nails. Tony: They are, Kev. But they've got fuck-all to prove to anyone.
And in the same universe, Midnighter: the leatherclad, nigh-unbeatable, Majestic-level superhero with a penchant for slasher smiles and gleeful dismemberment, and probably the most roundly feared of all the Wildstorm protagonists. Also, openly gay and fond of experimenting with his hair.
From Adam Warren's Empowered, there's the goddamn Maidman, who's Badass enough to fight crime wearing a maid's costume and stiletto heels. Imagine Batman in drag, and just as feared and revered. That's what you're dealing with here. Also very serious about his laundry. Because bleach doesn't get out bloodstains.
Everyone knows Steve Rogers, right? The accept-no-substitutes Captain America, paragon of all that is good, patriotic and manly, a statuesque, muscled beacon to heroes the world over... and enthusiastic artist. He was a professional illustrator occasionally when he had a secret identity, and once ended up drawing his own (licenced) comicbook. Let's face it, if Captain America does it, it's not girly: it's awesome.
That may derive from Most Writers Are Male, as the guys making the comics want to be seen as manly, so what could be more manly than something done by Captain America? And if it's manly, Cap has to do it, so he illustrates and because illustrating is manly the writers... aso.aso.
Issue #225 (9/1978) shows Cap as not always being a seemingly stereotypically macho man. He was also often described in other origin retellings as being sickly, frail and avoided rough play as well as spending a lot of his childhood avoiding bullies through staying inside drawing (and being teased for having such interests, so in one origin retelling it was stated that art was a secret hobby) and having his childhood best friend Arnie Roth as his protector. So while art isn't necessarily a "feminine" interest, it does get treated like one for him and is a strong link to his past. And as for the icing on a cake, in issue #2 (4/1941) Steve shows while undercover an ability to knit.
Leslie in Liberty Meadows cries while watching Touched by an Angel, but changes the channel to a wrestling match and starts grunting when Ralph enters the room. Of course, it would be hard for Leslie to be described as a Real Man, even if he weren't a frog.
Though with a name like Leslie, his masculinity is probably called into question now and then.
Harsh gangster Suhnshyon Tzang in Bowling King is fierce, competitive, and intimidating. He also loves Britney Spears music and wears facial make-up often.
Although it's possible that it only affects alternate Wolvies, Exiles stated he also likes karaoke and doesn't talk about it. And also in the series, Morph mentions that Mimic knows too much about figure skating than any male superhero should.
Considering how much time Wolverine has spent in Japan, it would be weird if he didn't enjoy karaoke.
Gambit of X-Men fame originally wore hot-pink pants and/or shirt as part of his uniform. In some iterations he still does. In the 90s animated series, at least, the pink on black outfit is not only the uniform of the Thieves Guild he was part of, but also body armor.
Nineties Anti-Heroes in general are prone to wear costumes way too colorful for their gritty attitude. Yellow, pastel purple and pink are not uncommon at all.
Roadblock from G.I. Joe is a world-class patissier, or pastry chef, and is an expert in many other forms of cuisine which he uses in his secondary duty as a military cook. He's also extremely large and powerful in his primary duty as an infantry machine gunner and can lug around a M2 Browning machine gun (which is typically used as a squad weapon since the whole thing with ammunition weighs 134 lbs) as his personal weapon.
The unquestionably badass Gung Ho is probably the hardest and meanest Joe of them all. He's also a mama's boy whose real name is Ettienne R. Lafitte and whose first language is French (he's from Louisiana).
Hulking cyborg soldier Matt McCoy in the Street Fighter comics from UDON enjoys gourmet cooking and playing acoustic guitar in his spare time. His commander, Colonel Wolfman, is a scarredBadass who wears a one-piece legless leotard and has fabulous hair.
In Big Bang Comics, BatmanCaptain Ersatz the Knight Watchman makes a living as a famous women's fashion designer. And on top of that, he lives with his grandmother. The Golden Age version added a yellow background to his insignia to make it look friendlier, too.
The Blue Blade in The Twelve. Truly, only a real man could wear frilly shorts, a cape, and a huge feathered hat, with boots and gloves, on national television.
And eyeliner, according to the sketchbook notes in either issue 1/2 or 1/4.
Sgt. Fluffy, Agent of S.C.H.M.U.C.K., from normalman. In his own words, a "heart-poundin', front-facin'" uber patriot and super action hero (he leaves out the part where he's a violent lunatic, but whatever), wears The Wizard of Oz style red sequined pumps throughout the series.
The living incarnation of Destruction in The Sandman gives up his cosmic responsibilities and tries his hand at creation; painting, dance, and flamenco guitar, among other hobbies. It all goes rather badly until he turns out to be quite a talented gourmet chef.
The X-Men's strong man Colossus is not only an artistic painter, he was also shown in the X-Mansion kitchen preparing to make quiche in Uncanny X-Men #171. This was about a year after Real Men Don't Eat Quiche came out.
The Mighty Thor always reads florist magazines while waiting for the local tailor to repair his cape. Of course, his wife Sif is an earth goddess — she probably got her husband involved in her interests.
Like getting their hair curled the same way.
Commander Prothero in V for Vendetta is a formidable man - who collects dolls.
The Last Czarnian, Lobo, who once killed, barbecued and ate a whole planet full of Easter Bunnies, once shed a single tear just thinking about his beloved space dolphins.
In the comic book Nexus, put out by First Comics back in the 80's, there was a character called Judah "the Hammer" Macabbee, a professional wrestler who once fought a championship match and between rounds demonstrated how to bake his prize-winning souffle.
Green Lantern Kyle. Based on some of his constructs, the guy reads a lot of Shojou.
In The Transformers, the Generation 1 Marvel Comics, there are quite a lot of Decepticons who wear pink - but are scary/buff enough to let this be acceptable: Fangry is an Ax-Crazy psycho, Carnivac is a badass turncoat, and Spinister is the cool professional.
Several predominantly purple Decepticons are widely and properly regarded as the most lethal thing on the planet, including Shockwave and Galvatron.
On the Autobot side of things, the leader of the Wreckers is decked out in silver, purple, and gold. This stereotypically feminine color pattern might not sound intimidating to start...until you learn that the laser cannon on his shoulder is the least of his arsenal, given how he has a massive, jagged harpoon in place of his right hand and uses a detached gun barrel to bludgeon people to death. He's also a sociopathic war criminal in one continuity and a remotely-controlled zombie ex-transforming robot in another. Heroic Autobot Impactor, ladies and gentlemen.
Marvel Comics' sentinel-from-the-future, Nimrod, was a big pink robot. He was also one of the deadliest opponents the X-Men ever fought; just surviving a fight with him was an accomplishment.
During the time when Wonder Woman served as Themyscira's ambassador in the U.S. she employed a gourmet chef named Ferdinand. Who is also a heavily muscled seven-foot minotaur (or "kithotaur", being from the island of Kithira).
In an Archie Comics story, Archie's mother tries to interest Archie's father in needlepoint, which the father insists is "for women only". When he discovers that the family surgeon made a first-prize-winning example of needlepoint, he threatens to find a different surgeon. Then the mother calmly suggests that while he could find a nice, manly surgeon who's all thumbs, she'd rather stick with someone who knows how to handle a needle if she ever needs stitches. Cue the backdown.
Whenever The Phantom has to visit a bar, he orders milk. The local toughs invariably try to pick on him for it. This never ends well.
Jon Sable, Freelance: Badass mercenary Jon Sable has a secret second career as the author of a best-selling series of children's books about a clan of leprechauns living in Central Park.