Written by wordsforghosts, "A painting or a stain" is about a stretch of life that feels drained and stuck. The speaker pictures the future as a big painting whose colours are fading, running from thick paint to thin liquid and then to nothing. Nothing new is being made. Everything just repeats and leaves you back where you started.
The title asks whether what's left is a finished work or only a mark that won't wash out. But the poem doesn't stay in that gloom. The speaker remembers that the colours have come back before, "eventually," and imagines flames flaring and embers turning into a fierce, even dangerous fire. That could be energy, anger or passion returning.
The mood is tired and quiet, with a small, cautious hope. The two "perhaps" lines, and the trailing ellipsis after "you will change," leave the ending open. The speaker doesn't promise recovery, but they allow for it.