They're primarily blue. The blue of an ocean from a destination holiday - the kind of blue you'd chuck on Instagram without a filter and still not be able to fully capture. That pure blue of hope and joy.
But when things aren't going well, they turn red. The whites bloodshot with anguish, a pained shade of crimson magnifying the bags under his eyes you're sure weren't there a few moments ago. Few wear disappointment as evidently, to the extent that when Buttler's eyes "go", his team-mates, particularly those sat around him in the dressing room, know something isn't right. That a guy who is never far away from the cheer needs that difficult combination of distance and an arm around the shoulder. If Eoin Morgan was an England captain you wouldn't want to play poker with, Buttler is the one you'd fancy your chances against.
On Sunday in Melbourne, stood on his own ahead of the post-match presentations after the T20 World Cup final, Buttler's eyes were red once more. This time, for much happier reasons.
There is a superficial dichotomy between Buttler the cricketer and Buttler the person. One's cold, the other's warm. One prides himself on bringing the noise, the other the quiet listener. One is brash, the other bashful.
Long before Morgan retired in June, there were questions about his replacement. Of course, Buttler was the only viable option, but with captaincy asking less of the cricketer and more of the man, there was a fear he would not have the necessary Morgan-levels of mettle for the job.
There's nothing like silverware to answer that question unequivocally. Over the last month, it has been made clear with each step towards T20 World Cup success that Buttler is the leader of a team who are vibing in his image. They have played brave, fearless cricket in challenging circumstances and, above all else, have done so without closing themselves off to the emotion of occasions but by embracing them. At this level, pressure is a privilege, and very few cricketers have adopted that mantra quite like Buttler throughout a fine career that now has some added gloss.
The truth is, Buttler the cricketer and the person have never been independent beings. Perhaps the best example of this came in the nervy chase of the 2019 50-over World Cup final against New Zealand. Just as he and Ben Stokes were bringing England back into their chase of 242, Buttler holed out to sub fielder Tim Southee. When he returned to the dressing room, the hearts of his team-mates, already emotional wrecks at this point, sank that little deeper when they saw his face. The eyes had "gone".
On the verge of tears, Buttler, famed for his neatness, threw his kit to all corners of the room, and began thumping the physio table laid out in the middle with one of his pads. To him, his failure was soon to be England's. While he could barely stomach his own error, the idea that he was responsible for the fall of his team-mates sent him into a spin.
Kit scattered, he disappeared for long enough that, when Stokes had somehow managed to draw England level with New Zealand's score to take the game to a Super Over, no one knew where he was. Suddenly, Buttler emerged from the bathroom springing on his toes: pads, helmet and gloves back on, ready to go back out there. He struck a four off the final ball of England's Super Over, then had the presence of mind to take Jason Roy's throw in front of the stumps off the final ball of New Zealand's.
As England lined up for their medals at Lord's three years ago, Buttler made a note of turning to Jonny Bairstow and telling him how proud his father would have been of him. David Bairstow took his own life in January 1998 when Jonny was just eight years old. And while many of Jonny's team-mates will have thought it, Buttler, overcome with the occasion, felt compelled to say it out loud.
Men's sport is never more uncomfortable when it comes to talking about things that can't be quantified as processes or match-ups. Buttler, whose life has been forged in these environments, has always possessed an emotional intelligence to say what needs to be said and, more importantly, what people need to hear.
Long before he became captain, he was something of an unofficial confidant among the England team. Players speak often of how he is one of the best ears to call upon when you are doubting your own game. Batters joke they are reluctant to seek his counsel, on the off-chance he simply queries "why don't you just ramp it for six?", but always do and feel better for the positive reinforcement of their own games. As wicketkeeper, bowlers often leave his chats, whether in hotel foyers or in the early hours at the bar, better for it. Mark Wood credits a bar chat in 2018 as a key juncture in his career when he was beginning to doubt if he had what it took in white-ball cricket considering he was not taking many wickets at that point. Buttler then reeled off a list of high-profile names Wood had dismissed, and reassured him that his worth wasn't contained in the column at the end of his figures. "It really meant a lot to us," Wood said. "Where I was thinking doom and gloom, he put a positive spin on it."
The fruits of that particular chat have been abundantly clear over the last few weeks in Australia. Wood bowled at the speed of light, taking nine wickets at 12 in the four games he played. And such was the trust between the pair that Wood felt compelled to be transparent with his captain the night before England's semi-final with India, telling him his hip injury meant he could not take part in the match. It meant that prior to the final, when Buttler informed Wood he couldn't risk selecting him even though the player himself felt he could make it through four overs, the decision was taken with no ill-feeling. This was cold business with a human touch.
Perhaps, though, the best example of Buttler wedding personality with performance came in dealing with two allrounders who have ended up having standout tournaments for England.
During the tour of Pakistan, he sat Sam Curran down to talk about the role he wanted him to adopt in the XI. For the longest time, Curran has been an intangible cricketer: Good at batting, good at bowling, calm under pressure yet seemingly difficult to fit into a specific role. And thus, someone you never really know you're missing so you end up unperturbed when he's left out.
On that tour Buttler reinforced a few strengths: a left-arm angle, a surprising bouncer, a knack for cutters into the pitch at various lengths and a reliability, all of which made him a handy prospect in all phases of the game. That he was capable of bowling everywhere, clearing the fences and consistent meant he could hide in plain sight among the bigger names. Now, as player of the final and player of the tournament, he is a big name himself. Intangible and hidden no more.
With Stokes, things were a little trickier. A lack of T20 cricket - domestic or international - had England's Test captain as the elephant in the squad. You could never doubt his willing for giving his all to the team, but having not played a 20-over match in 15 months before arriving in Australia, such absence was only going to breed unfamiliarity.
Before a training session had even taken place down under, Buttler collared Stokes for a chat about how he saw his World Cup panning out. He'd be bowling a few overs - mostly the first and seventh - and play measured knocks with hitters around him, a part that became more pronounced when Dawid Malan suffered a groin strain. That latter role will deservedly take the headlines, with an unbeaten 52 to take the trophy away from Pakistan after an unbeaten 42 against Sri Lanka took England through to the semis. But the 16 overs across the tournament, and the six accompanying wickets, were the real success story for a player whose bowling had previously been found wanting in this sphere, even beyond the catastrophe of Kolkata 2016. "That 10-minute chat just made me really understand the way in which I can affect the game," Stokes effused.
Others might have left Stokes to work it out himself, or may have questioned the wisdom of trying to reinvent a player who, by global repute, has it all down. Buttler, however, took the initiative, seeing beyond the legend to recognise someone who needed to be put at ease.
"Relationships take time, and as you get to know people better and better, you build trust," Buttler said, long after the ticker tape had settled following England's victory on Sunday.
"I'd say the Pakistan tour - for the group, not just myself and the coach but for everyone involved, just seemed like a really good tour.
"Lots of bonds were built, and I thought we got back to playing some really good cricket there. It takes a bit of time to get to know people well and get to feel comfortable, and there's so much talent in the group that, as soon as we feel comfortable, we're a dangerous team."
It might hurt Pakistan double to hear their hospitality in September and October led to their downfall in November. The squad that arrived for the seven-match T20I series had a few notable absentees but the challenge facing Buttler and head coach Matthew Mott after an indifferent start in the 2022 summer extended beyond winning a few games.
Alex Hales made that trip, after years in exile following a failed recreational drugs test ahead of the 2019 World Cup. Bairstow's untimely golfing accident presented an opportunity for a recall after director of cricket Rob Key had mentioned Hales had been discussed in the meeting to confirm the original squad for the winter's white-ball excursions. But the door was only opened by Buttler.
He had long been sympathetic to Hales's situation, even if he was under no doubt the man himself was to blame for it. But there was also an appreciation of Hales' undoubted talent in the shorter formats, which were underpinned by the fact the pair had been close - Hales was an usher at Buttler's wedding - before the 2019 indiscretion.
Any return needed to be tactful, so Buttler took on the responsibility of making it so. While he could have pulled rank and brought Hales in, he instead called around senior members of the squad to run it by them. It was as much "this is happening" as it was "how would you feel about it?" The responses were positive, the end result even more so. Hales finished with 212 runs - the second most for England - and walked away with the team's top score (86 not out in the semi-final against India).
That Buttler facilitated this reintroduction so smoothly - hardly an English tradition - speaks of his people skills. Those are much ingrained as they are refined: Buttler is a voracious reader of books on high performance and management, all approached with an open mind in order to take elements from each without being tied too strongly to someone else's interpretation of those themes. Similar to how his batting is borrowed in parts: fierce wristwork from his days playing hockey as a kid or aspects admired off the likes of AB de Villiers and his Somerset hero, Marcus Trescothick.
At the same time, there have been moments throughout the World Cup when Buttler's self-conviction came to the fore. Following the Group 1 defeat to Ireland, he implored his players to dwell on the pain when some simply wanted to forget and move on, as is the way in T20 cricket with the next match always around the corner. Remember the pain and ensure it never happens again.
In the lead-up to the semi-final at the Adelaide Oval, Buttler decided to scrap the pre-prepared plans to bat first if they won the toss. "I think the majority of us were thinking: 'It's a great wicket, let's go out and put a statement out there,'" Mott recalled. "And he was really clear. He consulted and then he said: 'No, I think this is our best chance of winning.' And it proved a masterstroke."
By the final, Buttler had evolved into the captain many hoped he would become but few expected to see so soon. Tactically astute, emboldening, even a strong orator despite being so softly spoken. Considering it was only a few months ago he was using his stint with Manchester Originals in the Hundred to see if he preferred leading in the outfield rather than as wicketkeeper, the command of the job - behind, in front and away from the stumps - is perhaps the final cog in what has become a remarkable white-ball machine, one that has now become the first men's team to hold both limited-overs World Cups at the same time. Morgan put it together, Buttler has pimped it.
You wouldn't describe Buttler as a renegade. But he doesn't quite conform in the ways you expect of a kid who grew up in Taunton. The routes he has taken in the game have been conventional with the odd detour out of curiosity. He concentrated more on the white ball than the red one early on because that's where he felt his strengths lay, perfecting ramps and reverses without ever really fussing over the fact he hits the odd cover-drive through extra and in the air.
That he played as much Test cricket as he has - 57 caps - is through the pride of being English and the notion that that is the format that English cricketers strive for. That last bit comes from a long-held view that Test cricket is where you make your legacy and this idea that your career - and hence, life - is unfulfilled without it.
Maybe when this is all over, Buttler may regret not making a better fist of red-ball cricket. But in terms of worth to English cricket, his team-mates and fans alike, what he has provided in entertainment and special moments would have been enough to satiate him well before this World Cup success.
Now however, that contentment is greater. For Buttler's achievement has come about after demonstrating that the cricketer is in perfect harmony with the person, and is now undoubtedly one of England's greatest of all time. When he gets a moment to consider that, who could blame him if the eyes go again.