This surprises me. I was extremely skeptical of thee whole retina thing before I got a chance to use it. Now I can't see myself ever buying something with less pixel density.
Considering it's built in, it's light-years ahead of the junk that Windows calls a shell window.
iTerm 2 doesn't do this. It's the "accurate" one. If you prefer your colors the way Terminal mangles them, you'll have to set them that way. :)