There is no such thing as 'real’ absinthe, so it can't be illegal. Absinthe is just brandy macerated with herbs, the most common of which are wormwood, fennel and star anise. And the recipe for absinthe is generally unregulated.
You can buy absinthe today that is ingredient-for-ingredient identical to the absinthe they used to make back when Van Gogh sliced his ear off.
No. Absinthe’s hallucinogenic properties are mostly just an urban legend. Wormwood, the plant that gives absinthe its name, does contain a chemical compound called thujone that allegedly has hallucinogenic properties.
No. Most old-school recipes are in the neighborhood of 68% to 72% alcohol (your average gin by comparison is about 40%), which meant people were getting completely wasted.
Add to that the liquor’s popularity among all those tortured artists of the era – many of whom were also smoking opium – and you've got a perfect recipe for an urban legend.
Wrong. Again, the definition of 'real absinthe' is non-existent, but in the U.S., absinthe was never even technically illegal. While you couldn’t call it absinthe, it could have been sold under a different name.
In most cases you shouldn’t judge the spirit by its color, but color may provide some clues as to what you're drinking. Most artisanally made absinthes range in color from chartreuse yellow to chartreuse green, but they can also be clear.