Adult PC Game: Natsu no Iro no Nostalgia by Moonstone Archive

When Ryouto awakened from his coma, the world seemed to have changed colour. This is because he gained a special ability which allows him to see people’s emotions as colours. For example, happiness shows as amber, sadness as sapphire, anger as ruby, and desire as emerald. Aside from that, he was like any other normal guy.