In the early days, ranges were not all sorted and set out - there was a lot of experimentation going on, Michael Harris was continuing to see what he could get glass to do, just carrying on from he was doing at Mdina, building on his experience constantly.
There may be a odd pink swirls with clear glass thing around somewhere.
Blue and pink swirls was never even really a "proper" range, nor were blue and white, or blue and clear for that matter.
The first established and named range was Seaward, in '73.