Sorry! Yes, rabbit language 101.1
And yes, to all the above.
Harlequin can be a breed or a variety (color). I try to use a capital for the breed and a lower-case for the variety. The same is true for Lilac and lilac, Silver and silver, Champagne and champagne, Chinchilla and chinchilla, Himalayan and himalayan, and Tan and tan: all can be used to refer to a breed, or to a variety name in several breeds.
A Harlequin is a breed (image from
Harlequin) which is defined, in part, by its coat pattern. Here is a Harlequin of the color group known as japanese:
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Here is a Harlequin of a different color, part of a color group called "magpie:"
View attachment 38070
They are called "color groups" because each group - japanese and magpie - comes in variations that depend on whether the colors are black or chocolate-based, and whether or not they are dilute versions of those colors.
Harlequin is also a color pattern, which is actually better referred to as a "variety" because as you can see above, the pattern comes in more than one color combination.
Here is a harlequin Dutch (which is the breed) from my friend's purebred Dutch litter:
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and here is a harlequin Mini Lop:
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Finally, harlequin is a gene notated <ej>. It is this allele on the E-series gene that causes all of the above patterns, plus the tricolor pattern, which is combination of harlequin <ej> and the broken-color allele <En> (which, confusingly enough, is NOT part of the E series but rather the En series). No other U.S. breed recognizes a harlequin variety, but breeds that recognize tricolor will always have some harlequin-marked bunnies popping up, since they are used to make the tricolors.
Rabbit coat colors, specially if you start by looking at harlequin genetics, or really any of the E-series alleles, can be a bit confusing at first.
@judymac gives a good introduction to the five primary coat color genes here:
https://rabbittalk.com/threads/good-rabbit-beginner-color-genetic-page.35580/
There is also a great book that covers basic genetic inheritance as well as rabbit coat colors:
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https://www.allthingsbunnies.com/ABC-About-Bunny-Colors-p/bks107.htm
Rabbit coat color genetics can be a proverbial rabbit hole, but it's a fun place to be once you get oriented!