Historical clue formulations

• The "i" of Roy G. Biv — 2022-03-07
• Only trisyllabic rainbow color — 2022-02-13
• Part of Roy G. Biv — 2021-07-30
• "Mood ___" (Duke Ellington classic) — 2021-06-27
• Only color of the rainbow not seen on the L.G.B.T. pride flag — 2021-05-30
• Deep blue — 2020-12-30
• Shade on the visible spectrum — 2019-08-22
• Rainbow color — 2015-05-24
• Spectrum hue — 2015-03-04
• Part of a rainbow — 2014-05-25
• Roy G. Biv part — 2009-09-09
• Shade deeper than heliotrope — 2007-10-12
• Rainbow shade — 2006-05-17
• Deep blue — 2004-05-07
• Spectrum member — 2004-05-02
• Rainbow color — 2003-05-19
• Color of Duke Ellington's "Mood" — 2003-04-21
• Blue — 2000-05-10
• Part of a rainbow — 1997-03-30
• Blue shade — 1996-03-28
• Musical mood? — 1995-02-16