How to cut a small amount into object? I want to make a poker chip with Blender. 

It would look like this at the end https://www.artstation.com/artwork/rGeB2 The little disks without the color. 



This what I have: 



I want to cut the orange part in a little on both the upside and downside of the object. When I tried doing this by scaling the z-axes down it pulled in the sides of the object as well. 

All I want is the orange part to be indented in.
Insert a circle; Extrude + scale it outside; Make inner rim an edge loop and extrude it along Z; Fill the inside and use Poke Faces on it; Extrude the outside rim like 0.01 more than the inner one; Select all and use Mirror modifier on it; Give the model materials.