This photograph shows a fireplace and painted wall in the front first floor room, today known as Wesley's Study, inside John Wesley's House.
The wall colour, a shiny green-grey oil colour, also once known as 'French grey' or possibly 'pearl', came to light during refurbishment works in 1994-5. It was found in most rooms of the house and, likely, it is the original colour. This would have been used throughout the house, probably excepting the main parlour, as it was cost saving. We know from the original building plans of the house that the rooms were painted three times 'in oil', and some rooms were to be got ready for 'papering'.
In the 1700s using the same colour for most of the house was the standard way of painting interiors, except in well-to-do households and mansions. See also the other photographs of the refurbishment of John Wesley's House, including 2012/13665.