The best matching paint (aside from have a body shop mix it) for an OX66 I found was the old Tempo brand. They have since been bought out by Moeller and I think the formula changed as their version doesn't match nearly as well.
This was after I shot the mids and lowers of my '98 225s with Moeller. Way too blue...
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I also tried the high dollar Colorite paint that is what Yamaha recommended. It was garbage.
Lastly, I have an old 25 Yamaha that I'm working on too. For that one, I took the cowling to the local Advance Auto and picked the closest matching Duplicolor spray bomb. The cap from the can is REALLY close so we'll see how the actual paint turns out. I would go this route if I were you.