The inserts are unfinished black plastic from the factory, most of them at this stage are faded grey. When we painted the entire strake graphite it looked like there was no depth to it and it appeared to be one large piece (as we know they are) but in painting the small inserts that connect the strakes a flat black, I was able to get more depth and make the strakes look like they were individual pieces. Much more visually appealing to me.

I will get pics when able, it is hard to comprehend from the description, but when you see it, it will be an ah-ha moment