Considered an intense color, Grulla's pigmentation within the hair shaft allows room for question. Sometimes described as blue or dove or mouse-colored, grulla has a somewhat complex pattern of pigmentation. The only horse that can be described as a light blue of soft grey is the blue grulla. The complex pigment pattern begins with an intense fine line of pigment migrating the full length of the hair shaft from the follicle. From this line, a thin curtain-like pattern of pigment is sent to the outside of the hair shaft. This allows light to come through the hair shaft directly to the intense core of pigment. However, since the light is not refracted completely from one wall to the other wall of the shaft, reflection of light from the "partition" creates haziness within the shaft. This is optically perceived as light blue or soft grey. The grulla's hide is comparable in durability to intense colors and is well-pigmented. As a result it can withstand extreme heat, pressure and sunlight. Sweat and heat seldom affect the refraction pattern in the shaft of hair. The heavily pigmented feet are usually thick-walled and can withstand rocks and hard use.

Look for an update on this article with genetic information soon.

Source:

• Green, Dr. Ben. The Color of Horses, The Scientific and Authoritative Identification of the Color of the Horse. Northland Publishing. 1974.

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Published August 1997 in North West Breyer Horse Club newsletter. (em)
© 1997-2019 NW Breyer Horse Club & Refiner of Gold Creations
Equinealities in place since 1997, Section in place 2001, Updated 1/27/2019