#(with zeke being a pale yellow while reiner is more of a bold orange tinted yellow)

[oxygenbefore1775]

mae u know why I’m here. give me The Big Rei Guy and the colour yellow!!!

eeee mar (although coming two months too late) i am ready to deliver

Reiner Braun

Funny you should ask because yellow is one of Reiner's "official" colors (the runner-up being orange) and I also tend to color code Reiner with yellow so let's work from from that.

Just like I've mention while discussing Zeke, yellow can be charged with both positive and negatives connotations which represent Reiner's development as a character. The virtues being the positivity, amusement and humor it represents - much like Reiner's outer facade when he was a Cadet, always cheering his comrades up and taking on a role of an older brother for everyone (not to mention the jokes he was making about asses and stuff). Meanwhile, the negative aspects of the color being deception and falsehood - again, resonating strongly with Reiner's experience of hiding his real identity and lying to his comrades about him being the Armoured Titan. This whole duplicity of color yellow perfectly describes Reiner's whole identity, the paragon of a perfect soldier he was trying to portray to the other and how it turned out to be a lie after all.

Another interesting duplicity that the color yellow includes is the fear/bravery dichotomy. The fear being the more popular interpretation of the either (hence the adjective "yellow-bellied"), it plays into Reiner's initial terror-inducing experience on the Island of discovering the unsettling truth about his unjustified instalment as a warrior followed by witnessing Marcel's death and then running away in fear without attempting to help. And yet - yellow was thought to be a color of courage in the Empire of Japan. It is the color of warriors, the very person Reiner has strived to be his whole life and eventually become by the end of the story as he helps in stopping the Rumbling.

One of the main ways that this color can influence people is its ability to cheer, instill optimistic thoughts. And even though it's not really representative in Reiner's personality but it is evident in the way he influences the people around him - first, it was Scouts, then the kids of the Warrior Unit.

All in all, yellow is a very fitting color for Reiner. Not only does it encompass his positive traits, but simultaneously cover the negative aspects of his personality as well, creating the ambigious portrayal that Reiner is known for, tragic yet also poetic in a sense