It would be nice if the sides of the arrows were painted color not grey
No. He means the top, bottom, front, and back of the arrows. They're grey in the picture.
I downloaded the bricks and looked at the blb files, should be a fast fix but I gotta go to bed. I'll look into tweaking it tomorrow.
On that note, though, thanks for bringing this up, because until just now I didn't even know there was a way to force a specific color on a brick within the blb. All my previous directly-edit-the-blb-files stuff was with things like the bevel brickpack.