Colour is Relative

Put a dull red next to a green and it looks bright. Put a bright yellow next to a bright orange and it no longer seems so bright. But if you decide hey i’ll slam a deep grey purple next to that yellow then it pops out like a blinding light. Try it sometime. Have you ever noticed the hills, mountains, buildings or sea turn purple when the sun sets? Or maybe you peered through the branches of a green tree with a warm golden glow from the sun and that distant mountain appeared far bluer than you remembered.

Colour reacts differently depending on what surrounds it.