Technically SVG doesn't require a colour. In absence of a fill colour renderers will render shapes in black anyway.
Furthermore, SVG supports masking already: http://www.w3.org/TR/SVG/masking.html#Masking – although the use of black there would mean transparent, not opaque. Wouldn't be terribly bad to align the feature with the spec in that regard, though. As far as I understood it, the intended result is essentially a single-colour image, masked by the given SVG.
Furthermore, SVG supports masking already: http://www.w3.org/TR/SVG/masking.html#Masking – although the use of black there would mean transparent, not opaque. Wouldn't be terribly bad to align the feature with the spec in that regard, though. As far as I understood it, the intended result is essentially a single-colour image, masked by the given SVG.