Style Place Order Button in Ascend

By default, this will be controlled in Theme Options> Basic Styling, Primary Color.  If you want to override the button and style it separate from your Basic Styling, add this CSS to Theme Options> Custom CSS:

div#inner-wrap
#payment #place_order {

background: #8b909a; 
-webkit-transition: background-color .4s ease-in-out;
-o-transition: background-color .4s ease-in-out;
transition: background-color .4s ease-in-out;
}

div#inner-wrap
#payment #place_order:hover {
color: #8b909a;
background: #000;
-webkit-transition: background-color .4s ease-in-out;
-o-transition: background-color .4s ease-in-out;
transition: background-color .4s ease-in-out;
}

Customize the CSS as desired.