Vincent van Gogh wrote to his brother:

[Eva Libre]

 

To his brother Theo, Vincent van Gogh wrote:

"I have new ideas and I have new means of expressing what I want, because better brushes will help me, and I’m really carried away by those two colours, carmine and cobalt.

Cobalt — is a divine colour, and there’s nothing so fine as that for putting space around things. Carmine is the red of wine, and it’s warm, spirited as wine.

So too is emerald green. It’s false economy to do without them, those colours."

"Bouquet of Flowers in a Vase", (1885)
by Vincent van Gogh
Gallery: The Metropolitan Museum of Art, New York