Read quickly, "Stand" seems to describe something drifting and alive, though the poem never names it. The opening lines pair colours that clash or contrast: red against white, grey against black, blue against purple. That sets up a feeling of opposition and unease before anything else happens. What follows reads like a creature, or perhaps a mood, that floats without purpose, covers the eyes, and hides from the world. It keeps bumping into others of its kind and hurts itself each time.
Judging by the imagery, it could be read as depression, anxiety, or some kind of parasitic sadness that attaches to a person, the "host." It hugs tight, makes its heaviness felt, and soaks up the positive feelings around that person until it is full, then moves on. The tone is cold and observational, almost clinical, yet there is a thread of sympathy for the thing itself, since it causes itself distress too. The mood is heavy, lonely, and quietly unsettling.