This is a fine old telephone box dating back to the 1920s, I believe. The first official street box was the K1 kiosk, that appeared in 1921. The design wasn’t very popular as it was deemed old-fashioned and it went through two further variations within just a few years. Its life was short: a more recognisable booth, with a domed roof, came along in 1926.
The rooftop sign and fancy metal scroll on this green example suggest that it is one of the variants of the K1. Its windows don’t match any official variant, however, so I suspect they have been replaced at some point.
These old boxes came mainly in red and white, or in cream, but other colours were used in some areas (hard to tell what colours as the photos are in black and white). This forest green variant is at Boulters Lock in Maidenhead and perhaps the colour was chosen to match its rural, waterside position. Some places made even stronger adaptations, with Eastbourne stretching to two of these K1 kiosks with thatched roofs.
A colourful note: the use of forest green as an English colour term dates back as far as 1810 and Wikipedia tells me that is a representation of the average colour of the leaves of the trees of a temperate zone deciduous forest.
As a crayon it is older than me! It became a Crayola colour in 1957.
Copyright Debbie Smyth, 5 February 2016