-his barista look is a bit more fancy but maintained. under his coat his little vest has poofy shoulder sleeves! i figured it'd make his coatless silhouette cooler and more distinct. regarding the coat, i wanted to make his silhouette more top heavy, in contrast to robotnik's bottom heavy silhouette

-i wanted to give him a bit of a vintage look, in contrast to robotnik who has a very modern, techy look. that doesn't mean robotnik's influence is fully lost though (via the round plates on the jacket and long zippers on the sleeves). i also gave him gold detailing contrasting robotnik's silver

-there's a lot more purple in his design than his biker outfit in sonic 3, because perhaps after sonic 3, he becomes more of an individual instead of fully centering robotnik in his life. he has his own new sense of style to go with, alongside his new personal, signature color

-the third eye lense in his glasses represent enlightenment after sonic 3. the third eye looks happy in the logo, because he's more confident in himself as an individual post-sonic 3 and realizing his true worth to robotnik

-stone made the gun himself. while he does use cannons made by robotnik in sonic 3, he's more of a classic hitman kind of guy. robotnik could use his fancy machines any time, but good old fashioned methods can't be beaten sometimes

ok so. design explanations:

-he has red eyeshadow and eyeliner. his glasses are magenta, not purple. you mix red and purple what to you get, magenta. robotnik and stone together, right. he and robotnik are working together in stone's eyes, not just robotnik working through him alone