John,
 
I haven't got ready references, but I am a wine- and beer-maker, and
I know that light can effect these products. However, the alcohol
doesn't have anything to do with it. First, with wines, dark bottles
are traditional, and wine-makers are nothing if not traditional.
However, they continue to be used primarily for red wines because UV
apparently interacts with the tannins--or so I've read--and can cause
oxidation. A very similar effect is well understaoond with beer. The
light interacts with the organic molecules of hop resins. Most beers
which come in clear bottles have been highly filtered, and have low
hop rates. The characteristic "skunky" or "cardboard" flavor
associated with some imports in green bottles (not as effective UV
filters as brown bottles) is due to UV (taste a Heineken and you'll
know what I mean).
 
As for spirits, I cannot tell you except that dark spirits--whiskeys,
brandies, etc.--also contain tannins which may suscepitible to
degradation by UV.
 
I have even noticed that UV can oxidize white wines in clear or light
green bottles. I store my long-lived Chardonnays in a dark place for
that reason.
 
In short, I understand the problem with wine and beer, but the
science involved with spirits is beyond me, unless it involves
tannins.
 
Dan