This photograph was taken in the first floor Study of John Wesley's House, during refurbishment works in the early 1990s. It shows some of the original interior paintwork behind John Wesley's large mahogany bookcase, after the bookcase was removed for repainting the room.
Various paint schemes can be made out, but the original would appear to be a pearl (green) colour on the walls, and a darker green on the woodwork below. It is possible that the woodwork colour was originally 'French grey', a greyish-green, as this was specified for most of the house, but that it darkened with age and layers of grime.
As this was one of the rooms which was to readied for 'paper', according to the building plans, the finish on the upper wall is either a paper without pattern in a light pearl colour, or a paper which was painted over in this colour shortly after its installation. Either way, the colours give an idea of the appearance of the room in the late 1700s when Wesley lived in the house.
Note the geometric pattern on the upper wall. This is actually dust and grime, which has left an impression of the panelled back of the bookcase on the wall.
See also images 2012/13651 and 2012/13697 showing similar colours in the hallway and in a second floor room.