We could see the reflective color as way to tint the reflection like known from metals. I rendered a product shot but the black plastic is much to reflective. The slider is very missed. If you don't like the color, why not ignore the color and use the brightness only?
Rhino IOR for reflections - did you try high values like 8 or 20 for getting metal effects? I can set the IOR 0/1/8/20 and the look doesn't change.