The Thames nocturne of blue and gold
Changed to a Harmony in grey:
A barge with ochre-coloured hay
Dropt from the wharf: and chill and cold
As said in the description, it is highly believed that Wilde’s impressions-poems were inspired by the paintings of his acquaintance, James Whistler. Whistler was known for his Nocturne paintings, one of them being  Nocturne in Blue and Gold , depicting the Thames River: 

Impression Du Matin