Those do not look exactly like mine, but my prop is painted black. I happen to live about 10 minutes from MT USA in Deland, FL and have flown over to have mine looked at. They assured me that it was cosmetic and was a paint issue. My prop was installed in 2008 and now has about 850 hours on it and those small cracks have been there for several years now. MT told me they started using a different paint some time ago in response to this problem. As I said, that does not look exactly like mine, but that could be a different paint. I will be interested to hear what MT tells you.
MT USA has been great to work with and are very customer service oriented, IMHO. I will probably have them overhaul mine one of these days.