after installing 1.4.1 and choosing the Elegant theme the custom.css for the stream button color for the initial state but not for the hover/click states. Here is what I had working:
html body div#fd.es .btn-es-primary, html body div#fd.es .btn-primary {
padding: 6px 12px;
font-size: 12px;
line-height: 24px;
border-radius: 0px;
background: #3e465c none repeat scroll 0% 0% !important;
border-color: #3e465c !important;
}
html body div#fd.es .btn-es-primary, html body div#fd.es .btn-es-primary:focus {
color: #fff !important;
background-color: #3e465c !important;
border-color: #3e465c !important;
}
html body div#fd.es .btn-es-success, html body div#fd.es .btn-es-success:focus {
color: #fff !important;
background-color: #3e465c !important;
border-color: #3e465c !important;
}