Orange (colour) with green, of yellow with violet ... trying to make the colours intense and not a harmony of grey". In another letter he wrote simply, "there is no orange without blue." Van Gogh, Pierre-Auguste Renoir and many other impressionist and post-impressionist painters frequently placed orange against azure or cobalt blue, to make both colours appear brighter. The actual complement of orange is azure – a colour that is one quarter of the way between blue and green on the colour spectrum. The actual complementary colour of true blue is yellow. Orange pigments are largely in the ochre or cadmium families,
Colour revolution groups, even borrowing the colour orange from the Ukrainian revolution. In November 2005 protesters took to the streets, waving orange flags and banners, to protest what they considered government fraud in recent parliamentary elections. The Azerbaijani colour revolution finally fizzled out with the police riot on 26 November, during which dozens of protesters were injured and perhaps hundreds teargassed and sprayed with water cannons. On February 5, 2013, protests began in Shahbag and later spread to other parts of Bangladesh following demands for capital punishment for Abdul Quader Mollah, who had been sentenced to life imprisonment, and for others convicted