How to change shine

[Vortac12]

I am working on creating my own custom paint job for this bird. I am trying to make some areas appear to be a flat black while others have a chrome look to them. I have tried messing with the Alpha channel by darkening it and lightening it up to change the shine but that appears to not be doing anything. I am also trying to get the reflection to match the color of the paint, so to give off a deep green shine instead of the grey color. I know in previous repaints I have done, changing the alpha channel affects the glossyness of it and changing the color on the .spec changes that color of the reflection