Some point in harness item for a type of horse (7)

I believe the answer is:

brindle

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'some' is the definition.
Both the answer and definition are adjectives. Maybe there's an association between them I don't understand?

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for brindle that I've seen before include "Streaky" , "Animal streaked" .)

I've seen this clue in The Globe and Mail.

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