Rayman: Origins is a 2D platformer game with an immense range of colours. The game consists of a variety of world and levels with specific looks and themes. Each world will have an overall tone and colour palette but within those worlds will be collectibles or non-playable characters that compliment and harmonize the background quite well. The game does a great job at separating the foreground from the background. It does this by making sure that one is saturated more than the other and changing the contrast between them. For example, in this forested world in the picture above, the parts of the environment that our players can interact with are highly saturated and bright whereas the background is a lot darker and details aren't as easy to make out because of the lower saturation.
However in some other worlds the saturation and contrast are played out differently. In this water based world the background is a lot brighter. This gives the impression that light is piercing through the water an illuminating the background. The foreground on the other hand, is a lot darker and instead of being bright blue is more of a grey with tints and shades of blue to show that it's underwater.