This is likely referring to a specific light novel, web novel, manga, or visual novel title. Many modern Japanese titles are very long sentences that describe the entire premise (e.g., "Shirokuro: Taking care of my childhood friend who suffers from a disorder where they cannot distinguish between black and white / shapes..." ).
If you are looking for a story that combines the wholesome angst of Clannad with the psychological complexity of Monster , track down the full title. Until then, the phrase serves as a beautiful prompt: Whose black-and-white world are you willing to sit in until the color comes back? Shirokuro, Shikijoushou, Osananajimi, Sewa, childhood friend care, visual agnosia manga, Japanese light novel disability, monochrome perception story, taking care of sick childhood friend, anime caregiver trope. Shirokuro - Shikijoushou no Osananajimi o Sewa ...
Is it a wavelength of light, or is it the feeling of being understood? For the childhood friend, color returns not through ophthalmology, but through the sound of a familiar voice describing a blue sky. For the caretaker, color returns when he stops seeing her as a "patient" and sees her again as the girl who once shared his crayons. This is likely referring to a specific light