I can't delete songs from iPhone because it is shaded gray?

I was autofilling songs into my iphone till my computer just automatically turned off, I then looked at my iPhone and it had many songs shaded gray, so I figured I should just delete them and restart the autofilling or resyncing all of them back again, but now I can't delete the songs whether it's on my iPhone or on the iTunes itself? I feel like there's an easy solution to this, but I can't seem to find it.

Is there an easy way of getting rid of the shaded gray songs that does not even play but remains in my iPhone music list?

If your songs are grated just slide it to the Left, you'll see a Red Delete button, tap it. That's all there's to deleting songs on iPods or iPhones!
Peace & Good Luck.