Dye in the Sun

[Fazor]

Just a random question. I was sitting here at work and noticed the "Proud to be an American" window-sticker we had on our storm door looked odd. This is because the red dye that made up the stripes of our flag was completely gone, indistinguishable from the white semi-opaque background. Yet the blue from the flag and from the lettering was as blue as the day it was put up.

Anyway, just curious as to if this might be 1) due to the fact that the red dye would absorb the light from the higher end of the spectrum, whereas blue would absorb the light from the lower end
or
2) the more likely case that it's just differences in the chemical composition of the dye.

I guess this could go in Q&A, but it's more of a babble as it's not that important. And yes, since the red was completely bleached out I removed said sticker. Personally, I don't like seeing bleached flag stickers displayed.

[01101001]

2) the more likely case that it's just differences in the chemical composition of the dye.

Guess: Because of chemistry, high-energy ultraviolet rays break bonds on the red dye, yielding it non-red, faster than on the blue dye.

[Nowhere Man]

This has been my speculation. I've been in video stores where all of the boxes that are near the windows were bleached blue and white. I've assumed that the blue also reflects the harmful UV end of the spectrum.

Fred