The Grishaverse of Shadow and Bone is a sprawling world with many lands and styles of dress. Immense detail was put into the costume design in the series, and this is partly due to the strength of Leigh Bardugo's descriptions from the novels, according to costume designer Wendy Partridge in an interview with Goldderby.
In her writing, Bardugo chose unlikely color combinations, so it was a challenge for Partridge to make them work on screen. Regardless, the costume design in Shadow and Bone is beautiful and fits the mish-mash of cultures that the world draws from. With season two of Shadow and Bone confirmed, it will be exciting for fans to see what new costume designs Partridge comes up with for the new and old characters alike.
Colored Keftas
The Grisha, or the Small Science, is comprised of three orders, and each order wears a different color of kefta in the Second Army. Etherealki wear blue, which is why Alina, despite being a summoner out of legend, prefers to wear blue to fit in. Materialki wear purple, mainly seen on David Kostyk. Finally, Corporialki wear red, since they work with the human body.
The embroidery on each kefta matters, as it denotes which specific kind of power the Grisha wields. It's here that the odd color combinations come into play since the purple fabric is matched with red embroidery or dark blue with light blue embroidery. However, the dedication and detail put into the costumes make it work. Since attention isn't drawn to the embroidery, it's able to fade into the background.
Sunburst At The Fete
Alina, as the Sun Summoner, is the only Etherealki given a kefta with gold embroidery. Also, instead of twisting lines, the shape of her embroidery forms a sunburst on the back. The front and sides showcase the spokes of the sun.
During the winter fete in episode 5 of Shadow and Bone, she wears a black kefta, a mark of her esteem and power. General Kirigan is, after all, the only other Grisha who wears a black kefta. The belt on Alina's kefta is always marked with the double-headed eagle, a symbol of Ravka as well as Russia in real life, according to the Victoria and Albert Museum.
Kaz's Gloves
Kaz, due to a revulsion of touching people or things with his bare skin (as revealed in the books), always wears black gloves. The pattern on the backs of Kaz's gloves is called crow feather, according to the costume designer via Reddit. This is yet another element that fits Kaz's affiliation with crows.
According to Ines Gloves, gloves were a symbol of rank for the monarchy or kings and were often bejeweled and otherwise accessorized. Since Kaz's are fairly plain, it's clear they're meant for work, though his wearing gloves is another sign that he's the leader of the Crows.
General Kirigan's Ring And Clasps
General Kirigan is the only one who wears black, as he wields shadows. The embroidery pattern on his kefta is also meant to be shadow tendrils, according to Reddit. His kefta is also the only one in the show with several clasps instead of just one as a belt. The clasps, as well as his ring, show his symbol: an eclipse.
His ring, with its long extended knife-like section, is useful for cutting into the world and calling the shadows to his aid, and it's also strange enough that it's worth noting. Most people don't have rings that cut, informing the audience that the General is more than he first appears.
First Army Double Eagle
The uniform of the First Army, worn by Mal and his friends, Dubrov and Mikheal, has Ravka's double eagle in several places. Firstly, it's patterned on the cloth of the rough outer coat. The uniform also comes with a pin with the double eagle on its face. As the double eagle is Ravka's main symbol, it makes sense that it would cover the uniform of their main army.
The First Army uniform is partly made of leather, which would withstand the cold weather that presumably occurs in Ravka. Certainly, Mal and his friends wear all parts of their uniforms when they end up on the Fjerdan border while hunting Morozova's stag.
Golden Kefta
During the final battle on the skiff, Alina wears a golden kefta with black embroidery, befitting of her powers. She makes a striking couple with Kirigan in all black. The material is also shinier than something like wool would be, indicating that this kefta is meant to be more decorative.
This kefta, as Alina's final costume, also showcases her journey throughout the season, from a cartographer's assistant to the Sun Summoner of Ravka with the outfit to prove it. She has surpassed just being a cog in a war machine and has become her own badass person. Eschewing the black the Darkling wears (and that Alina wears at the fete) indicates that Alina's done taking orders from someone else about what to wear.
Cartographers' Uniform
Alina originally works as a cartographer for the First Army. According to Reddit, her First Army uniform comes with a patch indicating she's a map-maker and it looks like two mountain symbols crossing each other. Her uniform also looks like something a real-life soldier would actually wear and not like a costume.
The coat is meant to be worn in hard conditions and the cartographer's patch is the exact opposite of flashy. Alina's hardwearing uniform is also an indication that she's starting from the bottom in terms of status. She has nowhere to go but up, and up she goes when she is revealed as the Sun Summoner.
Ketterdam Hats
Jesper frequently wears a fedora, which were at the height of popularity in the 1920s, according to Revival Vintage. Kaz and Inej occasionally wear bowler hats, which were popular among the working classes in the late 1800s, writes History of Hats.
Though Shadow and Bone is meant to be set in the late 1800s, the Ketterdam atmosphere is more reminiscent of the 1920s, what with the themes around gambling and heists. Therefore, the fedora fits Jesper very well, while the bowlers help Kaz and Inej straddle both Ketterdam and the older world in Ravka.
Servants' Uniforms
Genya Safin, though she is the Queen's personal Tailor in terms of her Grisha powers, is a servant in the Ravkan palace, and is thus clad in a white kefta with golden embroidery. She is the only servant Alina truly gets to know, and one of the only true friends she makes in the Little Palace.
Tailoring isn't necessarily a skill used in battle, which is most likely why Genya is a servant to the queen rather than a soldier. Regardless, the white kefta helps her stand out, and Genya is clearly known for her skill since she helps out at the winter fete.
Ravkan Hats
The hats that Ravkan guards wear are prominently seen in episode 6 when the Crow Crew sneak into the palace's winter fete, in one of their most badass scenes in Shadow and Bone. Made of fur, they obviously resemble Russian Cossack hats. The hats even have the double eagle, which is also seen on Cossack hats in real life.
Though neither Kaz nor Inej are from Ravka, the hats mark them as Ravkan guards and probably make it easier for them to pretend and sink into their roles. Whenever a guest looks at them, they see a guard, not an intruder, which is exactly what Kaz wants them to see.