Your Queen Victoria 4d stamp is part of a set and your GB 2˝d purple on blue paper stamp (S.G.201) also belongs to that set.
GB Queen Victoria 1887 4d green and brown
S.G. 205 (Scott#116)
222,000,000 of these 4d stamps were printed.

The stamp colors should look like this but yours has been in contact with water, probably during soaking off, and the green ink, which is extremely fugitive (easily washed or altered by water), has changed to a lemon color and makes the stamp worth very little. Only the head plate green ink is fugitive which is why the frame color is good.