martin has explained that "'yellow' refers to the mood of the band. brightness and hope and devotion." the references in some of the song's lyrics, including the swimming and drawing a line, "are all metaphorical slants on the extent of his emotional devotion". the drawing of a line refers to martin's habit of writing lists and underlining those important things on the list. martin has commented that the song is about devotion. he refers to his unreturned love (martin was single at the time he wrote the song). most people have considered "yellow" as a happy song, even though the lyrics do not seem to be.