The poem reads like a small piece of advice the speaker is giving, perhaps to themselves as much as to anyone else. When everything feels drained of color, the first step is practical: check whether you're just looking through a window. Maybe the dullness is a matter of glass and grey clouds rather than the whole world going flat.
If the sky is overcast, the poem suggests turning to memory. It lists a sunny day, dogs in a park, a forest, an ocean. These images are plain and short, and they arrive almost like breaths between the sparse lines.
The mood is quiet and gently hopeful. The speaker doesn't claim that sadness is an illusion, but offers a way to test it and a few bright things to hold onto. The white space around the lines makes the comfort feel tentative, as if the speaker is choosing each image carefully and trusting it to be enough.