ઓઠું તોએ જડાઉ નંગ, ખોટા તોએ રંગ;

ōṭhuṁ tōē jaḍāu naṁga, khōṭā tōē raṁga;

Literally: Even if a cover, it is a studded gem; even if false, it is a color;
What it means: High-quality materials or noble origins retain their value even when used as mere covers or in lesser roles.

Also said as

ગુજરાતી કહેવતસંગ્રહ (Gujarati Kahevat Sangrah) (1923) · read from the scan by machine — the Gujarati itself is unchecked · English is machine-made and nobody has checked it yet

Heard it differently, or know we've got the sense wrong? Tell us — that is exactly the kind of correction this needs.