Do Seurat's dots really mix into new colors in your eye?

Not quite, and that's the fun part. Georges Seurat invented Pointillism, painting pictures out of small, distinct dots of colour, because he believed your eye would do the mixing. The idea came from science. The chemist Michel Eugène Chevreul had found that two colours placed very close together look like a third colour from a distance. In theory, the separate colours of light bouncing off each dot would mix in your eye and brain, the way red, green and blue dots on a TV screen blend into every colour. That kind of mixing is called additive, and red, green and blue light together add up to something close to white. Painting, by contrast, is subtractive, and mixed paints tend to look duller.

Seurat spent two years on his most famous painting, A Sunday Afternoon on the Island of La Grande Jatte, finished in 1886 and about 2 by 3 metres. He made about 60 studies for it. Critics mocked the style, coining the name "Pointillism" to ridicule it.

Here's the twist: his dots don't actually mix additively. They aren't close enough together to fuse. Instead, strongly contrasting colours sit side by side and create what's called simultaneous contrast, a gentle shimmer that makes colours look slightly more intense. Pointillist paintings do often look luminous, partly because no pigments were mixed and bits of white canvas peek through. Seurat got his glow, just not by the route he planned.