I'm a size 12 and the 4X fits me - (I'm 5'7" and they're slightly long on me) - however I was hoping they'd be opaque like the photo shows.  I wouldn't call them sheer, but they're definitely not opaque.  I'm keeping them because they were cheap, comfy, I like the color, and think I'll be able to use them with something in the future... no idea what.
As for the color- they do not look like jeans at all, but if you pick the "denim" crayon out of your Crayola box, thats about the color.