as costume designer kelli dunsmore tells tudum, charles’ signature red polo turned burgundy in ep 3, to reflect his turbulent emotional state.
"then we find out that beautiful whole story of charles' past, and it goes black," she says. "in the middle [of the season], he goes all black — his harrington jacket is black, his polo is black." yockey praises dunsmore for coming to him and schwartz early with this subtle but very strong idea of "a way to visually track charles and his slide into self-doubt even though his base costume remains constant."
and if you look in ep 4, you'll see crystal and niko wearing red clothing, to support charles in his pain by donning his hero color.
but as charles continues his healing journey, his shirt "slowly goes back to burgundy. by the end of the [season], he's back in his red again," says dunsmore. "so he goes full circle."