The poem opens like a child's picture: sun, yellow; grass, green; sky, blue. The short, flat labels sound simple and confident, as if everything is in its right place. Then the speaker undercuts it. "It's all terribly cold still." The colors promise warmth, but the world hasn't delivered it yet.
The middle lines place us in an in-between time, "not yet summer barely even spring," with the seasons "threatening a change." That word choice is odd and telling. Change is usually welcome after winter, but here it sounds almost like a menace, as though the speaker isn't sure they want it.
The last line, "I can't feel a thing," works on two levels. It can mean the cold has numbed the speaker's body, but it also suggests an emotional numbness, a distance from everything around them. The mood is flat, quiet and a little bleak. The bright colors are there, but the speaker can't take them in, which is why the title, "Winter," seems to describe a state of mind as much as a season.