Morrow is a quiet poem about someone who spends her whole day waiting for the sun, which the speaker pictures as a "he." The sun's beauty is something she can't put into words. When he finally appears in soft pinks and baby blues, she is so struck that she loses her breath and stands there, memorized by the sight.
As evening comes, the sky turns to dark reds and purples, and she knows it's nearly bedtime and that he has to leave. Her heart fills with sorrow at that thought. The word "But" then sits alone on its own line, and the mood shifts. She won't be left empty-handed: she'll dream of his colours until she sees him again "in the morrow."
The feeling is gentle and a little wistful, like a crush or a long-distance love. The poem moves from longing to wonder, then to sadness, and ends on patient, hopeful comfort.