You can edit button materials in a similar way as with other materials. You can change the color of each thread and the button, independently of one another.
To edit button materials:
If the Materials tab is not already open, on the Resources tabs, click Materials.
In the Trims section, click the button. The button details are displayed in the Context view .
In the Context view , click the part you want to edit.
Near the top of the pane, there is a Single Color option. If you select this, the existing color thumbnails are hidden and replaced by one new color thumbnail.
Click on the color thumbnail to display the color picker and select the single color you want.
The color selected affects the the diffuse color only, unless you select Diffuse Color .