What color for colorblind

What color is an application with the purpose of helping color blind people knowing the colors of the environment around them.
It has two options of use: Take a picture and Chose from gallery this means that if you are colorblind and you need to know the color of a t-shirt you use the first option and you frame the t-shirt with the phone and than you tap the touchscreen where you want to know the color.
It recognizes all the colors and their shades.