Virgil’s assessment: Chromium oxide green is opaque and fairly lean, with higher tinting strength than terre verte. It works particularly well for verdaccio underpainting in mixtures with lead white. Useful in portraits and landscapes. [Included in his portrait palette.]
Terre vert is a natural earth color, transparent and low in tinting strength, high in oil content. Unfortunately, many paint companies are calling various mixtures of other colors by that name, which just creates confusion. Real terre vert is not a mixture of any other pigments.