These color combinations work for the "stacked" versions of the logo as well. Remember, on dark or non-white backgrounds, there should always be a thin white stroke on the outside of the Block N logo ...

So if your Reshirmam's special background is black, fuse it with the Kyurem that has a white background. And if your Zekrom's special background is white, fuse it with the Kyurem that has a black ...