Just to be sure I understand what is going on: showpiece.php also renders the white SVG files as a raster bitmap, after replacing the #f9f9f9 by some other color? And then saves this bitmap as a PNG image with palette encoding?
I know for sure that all areas of the images you mention that must be recolored are filled with #f9f9f9. Otherwise the rendering of the black pieces with fen2.php would not have worked. But there the inside of the Rook is always blue.
So the problem is not in the SVG; it must be in showpiece. It must overlook one of the #f9f9f9 strings when it replaces those. That it always does it in the Rook part suggests that the string is in some special context there that prevents it from being recognized by the substitute command. These images are all composits, and they were probably made by Greg (I usually relied on fen2.php's ability to combine SVGs on the fly, without first making SVG for those) with Inkscape by combining the existing SVG images of the pieces they combine. Perhaps this combining created the context that prevents the recognition of the color string.
The bbadger.png looks weird. I suspect something has gone wrong in creating the palette. Perhaps an overflow of the number of colors. It is all the pixels that would interpolate blue and black that seem to be missing.
Just to be sure I understand what is going on: showpiece.php also renders the white SVG files as a raster bitmap, after replacing the #f9f9f9 by some other color? And then saves this bitmap as a PNG image with palette encoding?
I know for sure that all areas of the images you mention that must be recolored are filled with #f9f9f9. Otherwise the rendering of the black pieces with fen2.php would not have worked. But there the inside of the Rook is always blue.
So the problem is not in the SVG; it must be in showpiece. It must overlook one of the #f9f9f9 strings when it replaces those. That it always does it in the Rook part suggests that the string is in some special context there that prevents it from being recognized by the substitute command. These images are all composits, and they were probably made by Greg (I usually relied on fen2.php's ability to combine SVGs on the fly, without first making SVG for those) with Inkscape by combining the existing SVG images of the pieces they combine. Perhaps this combining created the context that prevents the recognition of the color string.
The bbadger.png looks weird. I suspect something has gone wrong in creating the palette. Perhaps an overflow of the number of colors. It is all the pixels that would interpolate blue and black that seem to be missing.