Is black a colour? Black isn’t in the rainbow, but where does it fit in the colour spectrum? What makes something appear black? An expert explains how we perceive black.

Hidden layers of colour in the plumage of tanagers and some other songbirds explain what makes them so eye-catching ...

Many animals possess the fascinating ability to change colour. Chameleons adjust nanocrystals for temperature control and communication. The Cyanea Octopus uses chromatophores and texture changes for ...

It is easy to calculate the integral colour of the background if we adopt Milne's view that the galaxies are really receding. Then the light of a galaxy is shifted towards the red according to ...