Pink and bue are both common colours throughout IoWSG's history, there would not have been any "left over". It was only enamel that came from Mdina that was in short supply and not available in that exact colour, here.
But this period in the early '70s was a bit more free with experimentation than later on, once several designs had become established and from there on, new ranges got developed.
Then there was all the experimentation with William Walker (circa '79) when they developed their method for incorporating silver foil into glass for the Azurene ranges.
Michael Harris invented a special marver with tiny holes in its surface, under which air could be blown, to create a tiny vacuum pressure to hold foil flat on the surface so it could be picked up on the gather. He didn't patent it.
Then they had to work out how hot they could allow the glass to get without destroying the silver metal and having it start to react with the hot glass to create colours.
I've got a big cylinder that had been going just fine - until they put the rim into the glory hole and burnt all the foil around the top. It's all cloudy blue.
