The opaque condoms fit over clear incandescent bulbs - which are not affected by the guidelines - to give a similar effect to the banned bulbs.
Here's some text from Maurer:
The Euro Condom consists of a thin, heat-resistant silicone cover that turns a clear bulb into a frosted one. Frosted bulbs will be banned by the new EU guideline on light sources beginning September 2009, because they are said give off less light than clear bulbs.
But according to the specifications of various manufacturers the difference, measured in lumens, is negligible or not existing. – Protect yourself from stupid rules, use the Euro Condom!