Colors of Cancer Bracelets Mean?

I've begun my Monday's chores: washing clothes, straightening everything after the crew left, etc. and I have made my morning trek to Curves. (I met a friend on the way home from workout so we had to get a bite for breakfast; hope that didn't ruin the workout). Now, I'm stuffing envelopes to high school classmates with an encouraging word to attend our 50th class reunion coming up in the fall. We only have 42 left and I am hoping that all will attend.
Don's brother just called and, after a two-hour conversation, they have decided to meet tomorrow morning and spend the day together near their homeplace. It's interesting that they went years without contact and now they cannot talk or spend enough time together. I know they are making up for lost years and I think it's great. They are quite a pair, that's for sure.
I'm wearing 4 little bracelets which announce my support to cancer research. I have been trying to learn what the different colors mean but have only learned that the black one stands for melanoma. And of course, everyone knows what the pink represents. If you know what the colors purple, orange, red, or any other color mean I hope you will leave a comment. Someone said the others don't mean anything but I do wonder and question why not? I really do want to know.