The initial impression you may get (as I did!) is that this is a cheaply made coloured CFL.  Fact of the matter is that technically you'd be right - it's a very ordinary daylight colour temperature lamp with a very deep blue coloured paint applied none-too-evenly to the outer surface of the tube.

The reason for this however, is that this lamp dates back to before blue CFLs were readily available.  This lamp was intended to produce a cold blue/violet light in a decorative Christmas display - and as such was made-to-order.  This is why I've not been able to track it down in International Lamp's catalogues.  It doesn't exist in there, because it never did - it was custom made, I would imagine as part of quite a large order.

The output from these lamps is a very deep blue (as can be seen in the shot of it lighting my desk below) - the outer coating certainly doing its job very well - assisted greatly by the fact that a daylight temperature lamp was chosen as a starting point - I doubt it would have been anywhere near as effective had a warm white lamp been used.

While technically it's not a brilliant bit of kit - it's a bit of lighting equipment which was originally made to order, rather than an off-the-shelf part, hence is rather rarer and more interesting than it might otherwise be.  Not often you find custom made CFLs.  Of course, this lamp serves little purpose now that coloured CFLs are readily available, and is just an interesting bit of lighting history now.

Luxina and Pro-Lite products seem to bear a striking resemblance to each other, and I reckon that they may well be sourced from the same OEM, though Luxina (See related pages above)  is actually a registered trademark of International Lamps.  I also have Pro-Lite SCR-18W lamps (18W version of this) which are coloured as well - though these make use of a coloured phosphor rather than an external coating like this.  Otherwise the lamps are technically identical - even down to the noisy ballasts.