Well the image is made of pixels (at it's most basic) and you can get at the pixel data using the GetPixel method if you load it into a Bitmap.
That would give you a Color structure of the pixel value, which has an "R" property, which is the Red info.
Bitmap b = (Bitmap) Image.FromFile(@"D:\Temp\myPic.jpg");
Color c = b.GetPixel(0, 0);
But be aware that many colours that have a Red component do not look red!