What was the shortest-lived color?

Question

I've been reading about the history of the LEGO palette, most notably the transitions in gray and pink that have happened over the years where older shades were more or less completely replaced with newer ones.

What is the shortest-lived official LEGO color or shade? To be clear, I'm asking about shades that were officially released for public purchase as a set or individually (so no prototypes, test runs, employee swag, or third-party retints). I'm also not concerned about what parts were specifically made in that color, just the history of the color itself. If a particular color appeared in a 1x2 plate for two years, that part was retired, but the color was then used for a 2x4 brick for a year, that counts as three years for the color.

For example, have there been any colors that were released in only one set or theme and were fully retired when that set or theme was retired, never to be revived again?

Answer 1

According to the BrickLink Colour Guide, there have been three solid colours that were used for at most one year:

1. Fabuland Orange (1983; half barrel from Peter Panda Takes a Bath)
2. Very Light Orange (2000; only example being the aforementioned crouching cat)
3. Clikits Lavender (2005; four examples)

In addition, there has been one "chrome" colour (solid with metallic detailing) with a single-year run:

1. Chrome Black (2009; Darth Vader torso)

And finally two "speckled" colours, both from 2006:

1. Speckle Black-Copper (2006; Karzon Visor)
2. Speckle DBGrey-Silver (2006; three examples, all helmets)

As noted in one of the other answers, there are additionally some new colours for 2020. In my opinion it is too early to say whether these will have a single-year run.

Answer 2

Further to Alex's answer, from that source I found eleven colours that only lasted a year:

• Fabuland Orange 1983
• Very Light Orange 2000
• Clikits Lavender 2005
• Chrome Black 2009
• Chrome Green 1999
• Satin White 2020
• Satin Trans-Light Blue 2020
• Satin Trans-Dark Pink 2020
• Glitter Trns-Orange 2020
• Speckle Black-Copper 2006
• Speckle DBGray-Silver 2006

Of course the four 2020 colours may continue next year!

Fabuland Orange was only used for one item in one set for one year, so could be considered the rarest colour. The set was "Peter Panda Takes a Bath", and the part was Peter Panda's tub, a part barrel affair.

Answer 3

According to Bricklink, Very Light Orange was only used by single part for one year only - in 2000. It was used in 2 sets (Scala and Belville) and 1 "gear".

That part is this cat:

Another color is Clikits Lavender used by a number of parts (9, to be precise) for Clikits theme and these were produced in 2005.

Here's a picture by Ryan Howerter