If you do it the SAME every stitch you will get consistent results. Whether you run the left hand needle through first or the right hand, do it the same each time.
I think I would go with either straight saddle tan, or dark brown. Perhaps cordovan. When I look at it my eyes should be drawn to the inlay, and they are not.
Look into vg tan sheep. Muc thinner and far more supple than beef. You may want to 'break it in' a bit, but I use it for linin holsters and it is very 'bendable/foldable'.
Or kid skin.
I buy these chopping mats at the Dollar store (which is a $1.25 store these days) and use them to protect my bench top when dying or using cement. They wipe clean with alcohol.