The thermionic fabricator recipe to produce a regular block of glass uses 4000 mB of molten glass and 1 piece of propolis, whereas 4 blocks of colored glass only need 1000 mB of molten glass, 1 piece of propolis and a dye. I'll just assume these were meant to be the other way around? (1000 mB -> 1x glass, 4000 mB -> 4x stained glass)

Using Forestry v. 5.8.2.431 (from Jenkins).