This is the code that I used, remember that you need to use HEX colors and replace where it says insertyourcolorhere with the numbers and letters for your hex code do not duplicate the # also change the rest of the information to fit your needs:
<p style="line-height: 250%; text-align: center;"> <a style="background-color: #insertyourcolorhere !important; border-color: #Insertyourcolorhere !important;" class="si-btn si-btn--secondary" href="INSERTYOURLINKHERE" data-uw-rm-brl="false">INSERT NAME OF PAGE HERE</a> IF YOU WANT MORE THAN ONE BUTTON COPY FROM <A TO </A> </p>