Engine Bay color help

While the original reasons for the body color engine bay were likely driven by costs and manufacturing simplicity (not having to mask stuff, etc.) it has a nice flow with the rest of the car. It depends what you're going for. If you're after the visual effect of the engine standing apart from the rest of the car, satin black makes a nice, neutral boundary. Should you have some bizarre fetish for masking, a 1/2" checkerboard pattern of black and body color or some other pattern may be just the thing.

Personally, I'm a simplicity enthusiast.