Beautiful stamps NSK! Love the Army Official!
And you answered my question: The colored paper CAN be reduced to white over time... correct?
In terms of the strangeness, it's probably better to include more colors in the picture for reference:

You educated me in the past about the differences of washed-out colors from fugitive inks, but rather than being washed-out or dulled down (ones I have plenty of), the colors for the two above, which are at the top of this new image, seem to be enhanced.. Kind of "electric".
If all the color from the "colored paper" can be reduced to white due to water damage, I can't imagine the design color would look as vibrant as it does here.
What do you think?