A black plum is as sweet as a white.

Understand the thought

Meaning in plain English

An outward difference need not make one thing less good than another. The contrasting plums encourage judging what matters beyond appearance, without claiming that all differences are irrelevant or that their qualities must be identical.

What the words are saying

The black and white plums differ in appearance while the saying gives them equal sweetness. Figuratively, a visible distinction may be a poor reason to dismiss the qualities a person or thing actually offers. The image can challenge a preference that has not been tested against the relevant purpose. It does not prove that every pair of objects tastes the same or that appearance never conveys useful information. The careful reading asks which quality matters and how it can be assessed fairly. Applied to people, the comparison should support equal respect rather than reduce their worth to usefulness or ask them to prove they deserve it.

Everyday example

A group assessing two handmade designs tries each against the agreed requirements rather than rejecting one because its colour is unfamiliar.

When to use it

Use it when an outward difference is being mistaken for a difference in relevant quality.

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