I have that color as well, and I know what you're saying about the touch-up standing out. I had a metallic blue mercury villager that had some scratches on it (it was also 8 years old, so the paint had faded) that I wanted to touch up, I did one area and saw how crappy it looked and decided i'd just live with the scratches. Then the paint started flaking off, so I just got rid of the thing.

I did have a "beater" 95 4runner (it was a tan-ish color) that had a lot of rust spots on it... Since it was old and I was just driving it for the winter, I didn't care too much how I looked, so I attacked the scratches/rust spots with some sandpaper and rust stopper, then painted over it myself. The tan was definitely easier to blend with, but then again, I was using spray touch-up, not the pen.

Let me know if you find out a good way to do it, I'm sure there are gonna be a bunch of dings on my car lurking underneath the snow/ice/sand/salt. I can't wait to give it a good wash, those touchless car washes just don't do the job right