I don't remember where I found it but I had searched for a long time to determine the color of my ribbons and causes. I decided with the information and pictures I found - and actually when I looked at my tattoo under the light it is more of a tourquoise blue. I have red for heart disease, green for kidne disease, gray for diabetes and the blue/turqoiuse for Isabella's CDH. I gave a picture of the colors I found to my artist and he matched them.
I agree with your intention of not wanting to infringe on another group's awareness color, but in my research there are only so many colors in the spectrum and each color I found represented more than one cause. I would just like to see some uniformity. Since this seems to be unofficial, but the common CDH color so far, I decided to go with it. Either way, I know that the color on my ribbon stands for my grand daughter in my eyes. If it is determined officially to be another, I will just add it to mine - I'm flexible and just want to join in the support and awareness of these causes that are effecting so many families and lives §: )