Woman Reading a Letter (ca. 1663) by Vermeer, JohannesRijksmuseum
A private moment in Johannes Vermeer's Amsterdam. A woman in a blue cloak reads a letter at the window. It might just be the shape of her dress, but it appears as if she's pregnant?
That, and the map on the wall, might suggest her lover is far out at sea.
Nocturne: Blue and Silver - Chelsea (1871) by James Abbott McNeill WhistlerTate Britain
It's a rare, quiet night on the banks of the Thames. The lights of Chelsea are flickering in the distance and dancing on the water.
James Whistler intended the muted palettes of his 'nocturnes' to evoke something of a poetic vision and a dreamy, pensive mood.
Summer evening on Skagen Sønderstrand (1893) by Peder Severin KrøyerSkagens Museum
After a dinner party at artist Peder Severin Krøyer's house in 1892, Anna Ancher and Marie Krøyer went for a walk together along the beach, to enjoy the 'blue hour' of the summer's evening - when the sky and sea seem to merge.
The next year, Krøyer recreated that scene in paint.
Swimmers, Jávea (1905) by Joaquín Sorolla y BastidaSorolla Museum
The beautiful surroundings and the unique colour of the seawater in Javea (Alicante) fascinated the painter Joaquín Sorolla, and he painted many scenes of bathers.
In a letter to his wife Clotilde in 1896 he wrote that the landscape in Jávea is 'like a dream'.
Almond Blossom (February 1890 - 1890) by Vincent van GoghVan Gogh Museum
Vincent van Gogh painted this simple picture of his favourite subject - blossoming branches against a blue sky - as a gift for his newborn nephew, named Vincent in his honour.
He chose the almond tree as they flower around around in February, announcing the coming of spring.
Blue Horse I (1911) by Marc, FranzStädtische Galerie im Lenbachhaus and Kunstbau
The blue horse of this painting was a symbol of the German Expressionist group, Der Blaue Reiter, which included Wassily Kandinsky, Alexej von Jawlensky, Franz Marc, and August Macke amongst its members.
The group sought a free rein from the conservative values of the day.
Cow's Skull: Red, White, and Blue (1931) by Georgia O'KeeffeThe Metropolitan Museum of Art
This painting is Georgia O'Keeffe's answer to the 'Great American Painting'. A sun-bleached cow's skull mounted on a crucifix-like pole, backed by the red, white, blue of the Star Spangled Banner.
For O'Keeffe, bones didn't symbolise death, but the beauty of the arid desert.