Is the Blue label the Export label?
Yes, that's right

What is the age on these, and are there any *special* colors that are more collectible?
Swans were made throughout the years at WF. They can be seen in the 1938 catalogue and until the last, in 1980. However, the very last swans were 'footed', being sat on a blob of glass rather than having a polished flat base, and had only 3 wing pulls on each side, which is how you can tell the later ones. The early ones had 3 wing-pulls on the 6 inch size and 4 wing-pulls on the 8 and 10 inch sizes. Having mentioned sizes, there were earlier swans which were 4" and 5" but these are rare. Also, the heights do vary considerably, so should only be considered an average. It is possible to tell early swans by the shape, as earlier ones have a narrower head and a high tail, while later ones have a broader head.
From the heads I would say yours are from the in-between years, neither early nor late. Is the little blue one Sapphire or Arctic Blue? It's a bit hard to tell from your picture. (Sapphire was earlier, ending around 1960 when Arctic Blue - a more subtle grey-blue - replaced it. Ocean Green (a grey-green) replaced the earlier Sea Green at the same time.)
'Special' colours? Hardly worth mentioning Pink and Black, as they are the 'Hen's Teeth' or should I say 'Swan's Teeth'? :24:

The older colours, like Early Sky Blue, Emerald, Sanctuary (like 'Bristol') Blue and Amethyst are found less frequently, and one of the most sought-after is the later (but produced in lower numbers) Late Sky Blue. Silver swans are also fairly rare, as is anything in Silver.
I love WF swans, and I warn you they are addictive! (I now have over 70 :thud:) :smg:
Enjoy collecting them! As John says, they are so much cheaper than ducks, and IMNSHO much more elegant! :thup: