Because Boudicca was terribly worried about the way she looked.
The sources for Boudicca are Tacitus, Agricola 14-16; and Annals 14:29-39; and Cassius Dio, Roman History 62.1-12 ... having just read through them all, I can state that there is not a single mention of perfume.
Boudicca's Blue blooded perfume - The Telegraph:
Boudicca, Queen of the Iceni tribe, is famous for having led an uprising against the occupying force of the Roman Empire in AD 60/61 and legend has it she and her tribe of warriors wore a cobalt blue paint on their skin, which gave them a ferocious and mythical look when advancing into battle. When finally defeated by the Romans, Boudicca killed herself by swallowing hemlock – an extract of which is actually included in the new Boudicca perfume.According to Tacitus, Annals 14.37, she took poison, though which one is not stated. According to Dio, she died of natural causes [62.12]:
In the meantime, however, Boudicca fell sick and died. The Britons mourned her deeply and gave her a costly burial; but, feeling that now at last they were really defeated, they scattered to their homes.Hmmm, also I couldn't find a reference to her wearing wode, but that might be nit-picking ... though I look forward to the launch of Boudicca's wode blue eye shaddow ...
* - the name of the perfume
** - the name of the fashion company that produced it