Try to match it up to some automotive rattle can spray. Spray it into a cup or the cap and quickly dip a small brush into it and dab it on a little at a time. Quickly remove any excess on the good paint. If the head is powder coated avoid using any acetone as it might also remove the original paint. An auto parts store might also have a small bottle of touch up paint with a built in brush like toenail polish.
This is a Golf HOing Blog/site, right. I vote to buy another putter from LogicalOne and donating the "damaged" one to First Tee. Just a thought. This is why I bought two.
Bravopilot I actually have one last red one available that I saved too! 
LogicalOne See how easy that is?
Doesn't everybody buy at least two of everything?!
Subsonic Only when one buys the wrong color thinking they bought another. Too arrogant to admit a mistake.
HybridWood
I think you'd have a really hard time matching that same color.
What you could do is round off the other corner to match this side.
Being aluminum it's pretty easy to polish to a mirror finish and then
you could do a transparent matte or even a candy red finish.
Here's a friends old Bettinardi (similar thick shape) that I did some woop-woop to,
and powder coated a candy red....if you want a one of kind putter!
Wear your battle scars with pride. Did you drop that putter on the concrete? No. You hit a bear with it. Problem solved.
