I could not detect much difference through visual comparison
Did you zoom way in? If so, I can't see how you could miss it. It is literally the difference between these:
I took screenshots and replaced the original piece and space colors with the same color
I'm not sure what this is supposed to indicate, beyond the fact that they are different, but there are issues with your test. First, on #1 you have already corrupted the original output by going from SVG to PNG (vector to raster). Secondly, you didn't replace the original piece colors on #3.. I inspected the white pixels to verify that they are FFFFFF, so something went wrong with your expirement. And I still see dark pieces on #2, so probably something went wrong there too.
Did you zoom way in? If so, I can't see how you could miss it. It is literally the difference between these:
I'm not sure what this is supposed to indicate, beyond the fact that they are different, but there are issues with your test. First, on #1 you have already corrupted the original output by going from SVG to PNG (vector to raster). Secondly, you didn't replace the original piece colors on #3.. I inspected the white pixels to verify that they are FFFFFF, so something went wrong with your expirement. And I still see dark pieces on #2, so probably something went wrong there too.