A good horse cannot be of a bad colour.

Understand the thought

Meaning in plain English

An irrelevant feature of appearance should not make a capable person or useful thing seem inferior. The horse’s colour challenges a superficial judgment, while leaving relevant evidence about suitability open to examination.

What the words are saying

The proverb places the horse’s quality ahead of the colour of its coat. Its point is to question a judgment that treats an outward feature as a defect without asking whether that feature affects the purpose at hand. Applied to people or work, it encourages attention to relevant ability and demonstrated qualities rather than an arbitrary aesthetic preference. It does not say that every visible feature is irrelevant in every setting, or that calling something good settles all questions about it. The useful response names the criteria that actually matter and checks those fairly, rather than allowing an unrelated appearance to decide the assessment.

Everyday example

A club assesses a repaired projector by its working connections and clear image instead of rejecting it because its casing does not match the other equipment.

When to use it

Use it when an assessment is relying on appearance instead of relevant qualities.

Agent-assisted editorial interpretation. This explains the words; it does not by itself verify their author or earliest origin.