Ash was a shade of grey named after a certain substance.
The War Doctor wore ash leather gaiters when he helped Voord during the Last Great Time War. (COMIC: Four Doctors [+]Loading...["Four Doctors (comic story)"])
The Eleventh Doctor wore an ash scarf with his Victorian outfit. (TV: The Great Detective [+]Loading...["The Great Detective (TV story)"], The Snowmen [+]Loading...["The Snowmen (TV story)"])
Rose Tyler wore an ash grey hoodie during the 2006 Sycorax Invasion of Earth. (TV: The Christmas Invasion [+]Loading...["The Christmas Invasion (TV story)"])
Melody Pond wore an ash grey tank top with a raven black leather jacket as Mels Zucker. (TV: Let's Kill Hitler [+]Loading...["Let's Kill Hitler (TV story)"]
Ruby Sunday wore an ash jumper with maroon stripes in an alternate timeline. (TV: 73 Yards [+]Loading...["73 Yards (TV story)"])
Morris Gibbons wore an ash grey blazer when Sutekh returned. (TV: The Legend of Ruby Sunday|Empire of Death)