I really like how Tangled: The Series uses outfit changes to reflect the main character’s development. WARNING: OVERANALYSIS AHEAD.
Cassandra’s initial outfit (which will go here because Raps and Eugene’s starting clothes are established in the movie) is plain, subdued and practical, setting her apart from the other Coronans and the country’s bright and cheery aesthetics, while also showing her down-to-earth and reliable nature. The dagger on her belt and hidden one in her boot show that she is inclined to violence in her protectiveness of her loved ones, country and ideals and is a capable fighter who likes to be extremely prepared and self-reliant. The most dominant colour being dark red subtly foreshadows her connection to Gothel. But red is also the colour of the royal guards. Her own style is in all respects at odds with her pastel blue, flowing, lacy, demure handmaiden dress, showing us that she really isn't meant for or thriving in her job. Cass the handmaiden is not Cass, but merely a front, a box she’s been forced into.
Rapunzel’s Season Two outfit is sturdier and more practical than her previous more stereotypically ‘princess-y’ dress and has some darker and more muted colours, even outright black. This reflects this season’s more adventurous and serious tone and Raps’s personal increase in courage and confidence, and loss of innocence. The flower in her hair is replaced with a bird pin; she’s traded the symbolism of flowers, growth and renewal (from the renewal of her life as and growth into the princess of Corona), for that of birds, freedom and daring. This brings to mind the bird imagery in “Set Yourself Free” and the birds that flew past her way back when she first escaped the tower.
Eugene’s Season Two outfit is likewise more… swashbuckling. It’s the vibes, you know what I mean! The shoulder pad indicates that he’ll be doing dangerous, athletic activities, for example. The blue jacket is more similar to his most-of-Season Three one than it is to the old waistcoat. I’ll get to that in a bit, but basically what I say about that applies here but less so and minus the sun stuff. It’s kind of like the proto-Season Three jacket.
Cassandra is the only lead not to get any new clothes in the second season opening. Yes, obviously she’s changed a lot since Rapunzel came along (before that her father was the only close, positive relationship she'd ever had in her whole life, as far as we know). But in some very important ways, especially to her, she remains stagnant: she’s still in service to Rapunzel. Her existence is still legally considered inherently subordinate to Rapunzel. She goes on the journey in the first place with orders to protect Rapunzel, after all. Her outfit hasn’t changed because, handmaiden vs 'bodyguard' technicalities and Raps genuinely considering her an equal and friend aside… her role as ‘gal pal side character’ and servant in the heroine’s story is exactly the same, and Cass becomes increasingly attuned to this fact. And she isn’t happy about it.
Cassandra’s armour between “Rapunzel and the Great Tree” and “Destinies Collide” represents her reinforced emotional walls, her desire to protect herself from further harm and betrayal by anyone, but specifically her own friends, and most of all Rapunzel, who has just permanently crippled and traumatized her. She finally gets new clothes, the better part of a season late. Just like Rapunzel gets everything first, while she’s left waiting until she can scavage some armour from a random, forgotten knight, exactly who she wants to avoid being. Cold steel physically cuts her off from human warmth and affection. The deep red cape continues that link to Gothel. I think her new disability is important to this outfit. It’s firmer to limit her withered arm’s movement and provides it with better protection and insulation, possibly acting as an improvised brace, thereby giving us an impression of how painful and inconvenient the injury must be.
All of that applies tenfold to Cass’s black rock armour. It is literally indestructible, the way her toxic coping mechanisms are intended to make her, but that only highlights her emotional vulnerability in contrast. The blue right gauntlet draws attention to her formerly crippled arm, a sharp reminder of the pain that drove her to this point. Her skin turns ashen, implying that though the Moonstone cures her arm, it is (unsurprisingly for a power of death and decay) causing some kind of biological damage or sickness to parallel its toll on her mental health. Her theme colour besides black abruptly switches from red to blue, its near opposite. Her dark hair and eyes that connoted how grounded, sincere and trustworthy she was are turned a naturally impossible luminous blue, much more intense than her handmaiden dress’s pale blue. Her villainy is unnatural and wrong for her as her suppression was back then. But this is far worse for herself and everyone else. (“Waiting in the Wings”, which spells out Cass’s insecurities and ambitions that lead to her defection, occurs in a dark setting lit with blue moonlight, an early glimpse of Moonstone Cass’s black and blue colour scheme.)
Rapunzel’s Season Three outfit has elements brought back from her old dresses, like the puffy upper sleeves of the Season One princess dress and layered skirt combo with the front parting from Season Two, but it’s more elegant and refined than both of them. In a word, it’s regal. The colour gold is present for the first time in the cuffs, belt buckle and embrodered sun, connoting power and success and nicely complementing her purple. And of course, it matches her blonde hair that glows gold when she uses the Sundrop's magic. She truly masters that power from now on. This look befits at first her role of acting queen, and throughout the season her development into a wise, responsible, mature leader to her people. The sun symbol’s placement on her chest mirrors Cass’s Moonstone, contributing to the parallels between them that this season is brimming with. It also foreshadows the solid Sundrop’s manifestation there in “Plus Est En Vous”.
Eugene’s pre-promotion Season Three outfit is similarly more mature. He proudly wears the crest of the land he used to be an outlaw in on his shoulders, a display of commitment to Corona’s people and wellbeing and his own belonging there. Despite now knowing himself to be the heir to the Dark Kingdom, his home is and always will be Corona. That’s a significant step forward after his identity crisis in “Destinies Collide”. The knee pads are a continuation of his last outfit’s shoulder pad. There being two pads this time contributes to the outfit’s symmetry and adds to the professional feel. Like Cass used to, he wears a dagger, illustrating his protective role in his relationships and to his country (maybe royal guard foreshadowing?).
Eugene’s promotion to the captain of the guard brings his character arc full circle. The broken, lonely man who cared only for himself and mocked justice, clad in cool blue, has become a happy, loving and loved man who fights for justice and the greater good, clad in warm red. Again, there’s the Corona sun.
Cassandra’s ranger outfit combines various aspects of all her previous outfits to show the unification of her fractured personality and acceptance of all her past experiences and actions, the good with the bad: the overall structure is highly reminiscent of her original independent outfit, right down to the belt with a small blue pouch on one side; her maid's veil is tied around her arm; there’s a cape with an asymmetrical oval clasp like in the original metal armour; a special glove on her withered hand harkens back to the black rock armour, and perhaps represents her making peace with and accommodating for her disability; and Varian’s cassandrium crystal necklace is a memento of her friends in Corona. The primary colour of this outfit is green, the true opposite of both Gothel and that miserable, bitter handmaiden’s red, the colour of the growth and life Cass is leaving to engage in. Green is what she wore when she was a tenderhearted little girl - that very shade, in fact. She can’t restore her innocence, but she can still choose to see the world through new, more caring eyes. This is Cass.