Due to its warm colour, brown leather furniture creates a cosy environment. It is easy to match colours with as well, as it is neutral. Neutral colours, like browns and greys, are more or less a mixture of all colours, so they usually match up well with most of the colours of the spectrum. To keep that warm feeling that leather produces, though, stay with the warmer side of the spectrum -- reds, oranges and yellows.
Paint the walls a warm colour. Beige, sand or an off-white are safe colours, but you can also go bold with a deep orange or even maroon. The only drawback to the deeper colours is that they are darker as well, and will soak up the light, ultimately necessitating more lighting for the room. Be careful with colours like tangerine, which can look great at the DIY shop but which will overpower most rooms. If you want a very high-key colour for the walls, try painting a single accent wall in that colour, and paint the other three walls in a toned-down version of the colour.
Select rich colours for curtains that will inject colour into the room. Once your wall colours are set, think of colours that are in the same colour family for a harmonious match -- like pink to go with red, for instance. Because wall treatments take up less area, you can use stronger colours as accents.
Use pieces like throws as accents to jazz up the living room. Small pieces like this are also a good place to use eye-catching patterns like stripes or floral designs.
Acquire rugs or install carpets infused with colour. As the foundation of the room, the floor coverings can help set a colourful tone. Balance the strength of the colours with the rest of the decor you have chosen. For a conservative, solid base to the room, a soft gold or similar colour will do. An Oriental maroon or crimson rug may be a consideration, but, because a rug covers a large area, be mindful that intense colours may have an undesirable overwhelming impact.