A year or two back I had something very similar - perhaps a little taller and in blue - and like this one it was crude in all respects. I think Ivo suggested very modern, despite the antique appearance, and I seem to remember that Turkey was suggested as possible origin.
Not saying your pieces are definitely a match, but do look as though they might be.
Probably best not to use the words firing glass in the subject heading, as am sure this will get all the C18 collectors on a high

, although appreciate your reasons for using the expression, but it has to be said that the real things were usually quite refined in construction and never crude like these. I stand to be corrected, but suspect also that period firing glasses were probably made in clear glass only.