When I first saw this bowl I thought it might be one of Whitefriars 'New Studio' range in golden amber. It is 15.5cm diameter by 6 cm high, making it a bit larger all round than the typical 6 inch WF 9099 bowl.
However there are many things wrong in comparison with a standard WF 9099, including the size, the shape both inside and out, and the base treatment. I can't find any evidence that WF used the 9099 shape in the New Studio line. The coloured decoration also does not look like what was done on golden amber New Studio items, either. (That's so many things wrong, I now wonder what I thought was right. It is a bowl, I guess ...or is it an ashtray?) Nevertheless, it is a quality item in the same spirit as the New Studio line in that it has a freeform decoration in modern colours encased in the walls.
The questions remains: who made it and when?
Trevor