If you dont have the time / energy / confidence to paint your own eye cover - you could try asking your Mazda dealer.
My ND RF cover went missing several weeks ago.
I was planning to buy a replacement and the paint from MX-5 Parts.
But I figured I would try my local Mazda dealer.
They supplied two painted ones and one unpainted - 3 in total for 19.99
The took my number plate and confirmed the paint code etc. In the flesh the colour looks different to the rest of the car - but I suspect it it needed several more coats (as suggested above):
