title: How to change color of angular material stepper step icons
body: <p>In the angular material stepper component, each step is represented by an icon in a circle. The background color of this circle is set to whatever the theme's primary color is. Is it possible to change this color to the theme's accent color? I tried setting <code>color="accent"</code> on both the <code>mat-horizontal-stepper</code> component and each <code>mat-step</code> component, but neither one had any effect and I don't see a color input in the documentation.</p>