That dull complexion is what you want. The metal has now been etched and has a rust prohibiting phosphorus coating, ideal for paint.
That's interesting. I've had the exact opposite experience.
I treated an old joiner with rust speckles and got the same reaction. My cats, favoring tall horizontal surfaces, decided to use the joiner as a resting place. Within a few weeks, I had rusty paw prints. I talked with someone who worked on cars about it and he made some recommendations. So I retreated, then sprayed a thin oil which kept the rust away.
I ended up with oily paw prints everywhere though.
