Hair dye
From Tardis Wiki, the free Doctor Who reference
Liz Shaw used hair dye to dye her hair black in an attempt to avoid being recaptured by Pinpoint Division after the Third Doctor helped her escape Colonel Matthews' custody. (AUDIO: Intelligence for War)
In around 2311, Doctor A. V. Fairchild was expelled from the Plutonian Academy for committing retrotemporal citogenesis by breaching meta-time "to convince a minor player fated to an early death some millennia before the Cosmic War that she ought to dye her hair blue." (PROSE: Love & War [+]Loading...["Love & War (short story)"])