Do a web search for images on the NC35. They use a similar looking upside-down fork with black Nissin calipers. In fact, a typical breaking mod for NC35 owners is to swap the calilpers of the RC51. It's a direct swap!
"Exercise restraint and discipline, only responding to posts from legit customers and those with constructive positive intent, you will find that the handgrenades explode harmlessly. You have many satisfied customers who are happy to have the parts you've made. My suggestion to you is keep making good parts, keep getting more customers, take care of them and let them speak for you."
It could probably be done with any wheel paint from the auto parts store. Just don't use the brush on caliper stuff as it is more likely to look bad. You could mask the letters or paint over and sand them. I would mask them though. I got black ones because I hate gold, but they look a little faded, and I still have to get a rear caliper.
Here is a pic of mine with the flat black f4 calipers: