Helen Czerski starts her epic quest to uncover what color is and how it has defined our existence. She begins by seeking out the colors that turned Earth multicolored. To investigate the essence of sunlight, Helen visits the world’s largest solar telescope. She discovers how the most vivid blue is formed from sulfur atoms deep within the Earth and why red ochre is a key sign of life.

The raw, early Earth had plenty of color, but nothing compared with what was going to come. Green is the color of the natural world and yet it's the one color that plants have evolved not to use. Helen Czerski reveals the complex story of Earth’s natural colors and how the huge diversity of human skin tones reveals how humanity spread and ultimately conquered the planet.

Helen Czerski investigates the colors invisible to the human eye. To see the universe in a new light, she takes to the skies in a NASA jumbo jet equipped with a 17-tonne infrared telescope. We can't see in ultraviolet, but many animals can. Helen explores what the world looks like to the birds and the bees. With x-rays, we could look inside ourselves in ways previously only possible after death.