Ball Colours - Guidance for Manufacturers
An extended article on how the ball colour recommendations were arrived at appeared in the Croquet Gazette #339 (August 2012). This page is summarised from that article and letters to ball manufacturers in 2005 written by Lawrence Whittaker and Alan Pidcock.
** PLEASE NOTE: colour reproductions here will be very approximate, due to the variations in colour rendering on computer systems. For definitive examples, you must consult NCS colour samples. **
The Laws and Rules of Croquet state that balls shall be coloured (blue, black, red and yellow, alternatively green, brown, pink and white) but make no attempt to specify the colours. In other words, a ball shall be blue but there is no requirement as to which blue. For the most part this has not caused problems, but we are aware of cases where colours have faded with time and where balls have been confused when double banking is used. Thus a greenish blue has been confused with a bluish green, a reddish pink with a pinkish red, a dark green with black, and so on.
Consequently, the Equipment Committee has formulated recommendations of desirable ball colours. The aim is not to recommend attractive colours but those which will not be confused with others. Note these recommendations were formulated considering players with good colour vision - the difficulties introduced by colour vision deficiencies are being considered separately.
There are many systems for defining colours. Here we use the Natural Colour System (NCS) devised by the Scandinavian Colour Institute. This system has been used by various paint manufacturers, who print acceptable colour samples which are available through their distributors. A description of the system can be found on http://www.ncscolour.co.uk/. Samples of specific NCS shades may be ordered from suppliers listed on their website.
Each colour is described in NCS by the extent to which it resembles the "elementary" colours. There are four chromatic colours in which no trace of any other chromatic colour can be seen, i.e. red, yellow, green and blue. In addition, there are two achromatic colours, black and white, which contain no trace of the chromatic colours. Any given colour can have resemblances to two chromatic colours plus black and white. A particular purple, for example, could have 60% resemblance to red and 40% resemblance to blue. It would then have a hue of R40B. However, there are a large number of R40B colours, being pale or dark (their resemblance to white or black) and having more or less colour. A full description therefore includes the blackness, S, and the chromaticness (degree of resemblance to the chromatic colour), C. So the full description of a colour takes the form 1040-R40B. This is a light purple of 10% blackness and 40% chromaticness.
There have been no colour queries about Black or White croquet balls, so the following recommendations are restricted to the six chromatic colours. We have attached examples of some colours in our recommended range.
BlueHues between B and R80B (inclusive), with S<50 and C>=50. Aim for 1560-R90B to 2060-R90B. | |||
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RedHues between R and Y95R, with S<30 and C>=70. | |||
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YellowHues between G90Y and Y10R, with S<10 and C approx 80. | |||
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GreenHues between B90G and G10Y, with S<40 and C>50. | |||
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PinkHues between Y90R and R20B, with S<20 and C<=50. | |||
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BrownHues between Y30R and Y80R, with S between 30 and 50 and C between 20 and 60. | |||
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