"Disable Color" doesn't work with toggle buttons? How to set tint color of toggled off button?

To me it looks like a bug, that I can't use the tint color setting of the Toggle component labeled as Disabled Color.

There is an issue report about this. But its status is "By Design": http://issuetracker.unity3d.com/iss...isabled-color-when-it-gets-disabled-by-toggle

So, how do I set the tint color of a button that is toggled off?