Okay, so right from the start, I didn't like the look of the DX12 ab straps (as well as the straps between ribs). Here they are on the real suit:
They are a deep black, and they are pretty subtle. However, on the DX12, they are a grey - lighter than the abs themselves, which makes them pop - plus they are shinny. They draw your eye, and I had to do something about it. This comparison is crap, because I didn't think to take a flash "before" pic. Anyway...
All I did was paint the straps with a flat black acrylic. They are darker and reflect less light, meaning they are more subtle, which makes me happy. I know it's not a major change (and I suspect most can't even see what I did), but I like it. As you can see, I fixed that white spot on his lower right ab as well.
Here's a flash "after" pic:
To compare it to the stock DX12, look at the color of the leg plates. The straps are now that color on my figure, instead of grey.