What are you trying to accomplish?
I don't think that your plan is very likely to make you happy.
1. Color matching isn't that easy to do. Anything less than a perfect match draws your eye and looks bad.
2. Spray cans with minimum surface prep tends to chip or flake off easily.
If it was my bike I'd strip off all the old finish and start from bare metal or else just leave it as it is.
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My greatest fear is all of my kids standing around my coffin and talking about "how sensible" dad was.