Here we explore what meanings are behind the colors Juvia wears and what that says about her. I will underline anything i think pertains to her. This is more of a just for fun section. :)
It can be easily said that Juvia wears mostly blues. Within that, just about every shade of blue from pastel to navy, with a little of neutrals mixed in. First we will explore the color Blue:
Blue is the color of the sky and sea. It is often associated with depth and stability. It symbolizes trust, loyalty, wisdom, confidence, intelligence, faith, truth, and heaven.
Blue is considered beneficial to the mind and body. It slows human metabolism and produces a calming effect. Blue is strongly associated with tranquility and calmness. In heraldry, blue is used to symbolize piety and sincerity.
Blue is a masculine color; according to studies, it is highly accepted among males. Dark blue is associated with depth, expertise, and stability; it is a preferred color for corporate America.
Light blue is associated with health, healing, tranquility, understanding, and softness.
Dark blue represents knowledge, power, integrity, and seriousness.
To start with, I can say that the meaning behind blue reflects some dual aspects of her personality. Initially, in her dark blue wardrobe she is seen as serious, powerful and someone who has confidence in her abilities. On the flip side, she later switches to lighter blues in her wardrobe and is starts her evolution as a sincere, soft, loving, and faithful girl. Even after her switch back to darker colors she retains her softer, loving side. She is still powerful however doesn't always know how to tap into that. She loses some of her seriousness and confidence along the way. I would say Blue is her primary color.
We will now explore the next color that appears often: Black
Black is associated with power, elegance, formality, death, evil, and mystery.
Black is a mysterious color associated with fear and the unknown (black holes). It usually has a negative connotation (blacklist, black humor, 'black death'). Black denotes strength and authority; it is considered to be a very formal, elegant, and prestigious color (black tie, black Mercedes). In heraldry, black is the symbol of grief.
Black gives the feeling of perspective and depth, but a black background diminishes readability. Black contrasts well with bright colors.
While Juvia is initially seen as a mysterious, powerful, and elegant girl, I feel black does not always fit her in terms of color meaning. Juvia only wears black/dark gray long after the "evil" and mysterious part of her life. I'm a little surprised she didn't wear this color scheme first.
Lastly, we will explore the color White, which has appeared in some of her light blue wardrobe.
White is associated with light, goodness, innocence, purity, and virginity. It is considered to be the color of perfection.
White means safety, purity, and cleanliness. As opposed to black, white usually has a positive connotation. White can represent a successful beginning. In heraldry, white depicts faith and purity.
As seen with some of her lighter blue tones, faith and goodness is a common theme. Juvia is in all senses, an innocent, pure girl with good intentions. Combined with her light blue tones, it's a double whammy of goodness. She also starts wearing white at the mark of her transformation with Fairy Tail. While its not as present now, a lot of the attributes are still there.