However, during the last thirty years of the 1st century AD there was a marked change in style, with strong colours disappearing rapidly, replaced by 'aqua' and true colourless glasses.[1] Colourless and 'aqua' glasses had been in use for vessels and some mosaic designs prior to this, but start to dominate the blown glass market at this time.[7] The use of strong colours in cast glass died out during this period, with colourless or 'aqua' glasses dominating the last class of cast vessels to be produced in quantity, as mould and free-blowing took over during the 1st century AD.[2]