In Hello Charlotte 1, C is only seen briefly with an Executioner's Mask covering his face. However, his characteristic white ponytail can be seen. Hello Charlotte 2 shows more of his face, revealing bright yellow eyes. C wears a white, button-up school uniform and ties his hair back with a black ribbon. Due to being bullied, he is often shown with bandages on his face with some bloodstains. In the Happy Ending, C is shown wearing an outfit more similar to Seth's. He wears a high-necked purple shirt with v-necked whtie clothing over it with a red spiked halo above his head and longer hair. C is also given gloves by Charlotte to cover up his hands, which are damaged due to severe hand-washing.

(copied from wiki)