The cuttlefish can change colour despite being colourblind.
Why it is true
The cuttlefish has only one type of colour receptor cell in its eyes, making it colourblind. Even so, it can mimic the colours of its environment. Scientists believe it uses the shape and texture of its skin to perceive the colour of objects around it.
Source: Nature
Would you rather be asked first?
This is the reading side of the site, so the answer is in the sentence above — that is the whole point of it. Test yourself works the other way round: the question comes on its own, and the fact and the explanation only appear once you have answered.