This refers to the material's color (not the renderer's color). The material's color wasn't applied in the VectorGradient shader. This can be used as a workaround to tint the SVG sprites when GPU instancing is not an option. You can create an extra material, assign it to the sprite, and change the material's color to tint it. This is not the most efficient way to do it, but can be used as a workaround.