My point is, showing spine as white on X-ray (well, that's probably easy, but generalizing this to other tissues and their "normal"/"expected" color probably is

My point is, showing spine as white on X-ray (well, that's probably easy, but generalizing this to other tissues and their "normal"/"expected" color probably isn't) would be tremendously helpful in diagnosis... "peeking inside patients without cutting them up" - and I'm wondering, what's stopping us from doing just that?