This is what the purple B looks like when the color in the whole picture is corrected to make the background white. I can't say how close this is in reality - it's an approximate process - but I think it's in the ballpark.

We all know that purple is a mixture of red and blue. Take out a little blue and you have a redder purple. Take out a little red and you have a bluer purple. The white background in the original photo is quite pinkish - towards a redder purple. The correction (using an auto-correct white balance tool in Photoshop) is taking some red out of the photo and the result is bluer purple. As I understand it, the bluer the purple, the more likely it is that it's been nuked.

Food (and photos) for thought.