Filed from 4 published puzzles

SAPPHIRE

Set to 3 different clues across 4 published puzzles, most often “Deep blue” — The New York Times, Friday, 7 May 2004.

8 letters

Every clue on record, most used first

Deep blue2 times
The New York Times — Friday, 7 May 2004
Blue shadeonce
The New York Times — Saturday, 5 June 2010
September birthstoneonce
The New York Times — Monday, 7 February 2000

Other answers to these clues

ANIL4 letters
AQUA4 letters
AZURE5 letters
INDIGO6 letters
LAPIS5 letters
NAVY4 letters
OCEAN5 letters
SEA3 letters
SKY3 letters
TEAL4 letters