Please go to My Site → Customize → CSS (or Additional CSS), then add all of the following code to the bottom of that window.
/* This CSS makes the footer action button color match the site logo.
* 10766265-hc (jw)
*/
#custom_html-7 .action-button {
background: #8F1F34;
border-top: 1px solid #b06270;
}
Tip: keep the /*
comment */
in the code to later know what this code does.