I'm not sure If I understood your question correctly, but...
Create a button and apply a class, e.g.
awesome-button to it. Change its style to whatever width, height, shadow, hover effect etc you want. When you're done with your basic button simply add another class to it e.g.
red and apply new style, like fill color etc You can have 5 buttons with
awesome-button class and each button can have another class that stands for a color.
You can see that in
Question #1 on my just-created page
site :: http://forumhelp.webflow.com/#1
troubleshooting :: click me
To clarify, I'll post CSS for buttons I've created
padding: 10px 15px;
border: 2px solid #de6d40;
-webkit-transition: all 200ms ease-in-out;
-o-transition: all 200ms ease-in-out;
transition: all 200ms ease-in-out;
box-shadow: black 0px 0px 2px 0px;