French footwear designer Christian Louboutin's distinctive red soles have been given trademark protection, a US appeals court ruled yesterday (6 September).

Louboutin sued rival Yves Saint Laurent (YSL) in April 2011 over its use of what he claimed was his patented lacquered red on shoe soles.

The court found that the red sole is protected when it contrasts with the colour of the adjoining upper. The finding would allow Yves Saint Laurent to produce a monochrome red shoe with a red sole.

PPR-owned YSL claimed the result was a "full victory" and said that it was "extremely satisfied with this outcome".

It said the judgement ruled definitively that YSL is fully entitled to sell monochromatic red shoes, emphasising that it has been selling single-colour shoes since the beginning of the 1970s.

"The judge recognized the reputation of Louboutin red sole characterized by a contrast with the rest of the shoe, which has never been the case with any Yves Saint Laurent shoe. Indeed, this has always been the position of YSL since the beginning of the case and it was cited by the judge of appeal in support of his reasoning," said YSL.