Yellow and white are the only colours of tennis balls approved by
the International Tennis Federation, and most balls produced are
fluorescent yellow (known as "optic yellow"), the colour first
being introduced in 1972 following research by Vision scientists
demonstrating they were more visible on television.
In contrast, there is no official colour of a tennis court.
Naturally a grass court such as those used at Wimbledon (and back
in 1972 used at Kooyong) will be green. Until recently hard courts
have tended to follow the same pattern being dark forest green.
However, there are colours that perform better under certain
conditions. Ideally, a player wants to have the best possible
visibility for his or her game and to read the play, and this is
achieved by having the best possible contrast between the ball and
the surface. A dark green court surface, for example, provides a
good contrast to yellow or white tennis balls. Why? Because tennis
balls reflect more light (or, technically speaking, they have a
higher reflectance), and darker colours reflect less (or have lower
reflectance). Two-tone colour schemes are often selected to more
clearly define court boundaries. When such colour combinations are
chosen, the colour with the lowest reflectance (generally, the
darker colour) should be used within the court boundaries. However,
for areas in which tennis is played during the day, lighter colours
are often chosen for surfacing because they absorb less light and
therefore, minimize the surface temperature build-up so common at
the Rod Laver Arena. For night play, or for indoor courts, surfaces
with low reflectances will require more lighting to illuminate
them.
In 2008 the Australian Open followed the lead of the ATP Tour
and the U.S. Open with blue tennis courts. One reason for the
colour change was again television, Vision scientists having
determined that it is often easier for television tennis fans to
track the ball and read the play against a blue background. Down
under, all of the major tennis tournament sites and training
facilities are switching to the new tennis court surface used at
the Australian Open. In fact, as a result of the new blue tennis
court colour, the entire design of new tennis arenas in Australia
and elsewhere may be affected. For example, the colour and design
of tennis court backgrounds and seats, which usually complement the
colour of the tennis courts, may need to be altered. The rest of
the world may be "going green," but the tennis world is all
blue.
The picture below cryptically shows another way to improve
visibility and read the play. This will provide the cache
coordinates.
The cache itself is a 2 litre sistema, easy to access except for
the exremely high muggle activity at most times of the day and its
exposed position - discretion is advised.
