I found a solution for this:-)
i added these codes to custom css
#buddypress .comment-reply-link, #buddypress a.button, #buddypress button, #buddypress div.generic-button a, #buddypress input[type=button], #buddypress input[type=reset], #buddypress input[type=submit], #buddypress ul.button-nav li a, a.bp-title-button {
background-color: #ccc;
color: #fff;
font-size: 1rem;
}
and it did the trick ??
i found another problem with this theme and buddypress, the Create group button is displaying both in the header text, and in the breadcrumbs, and the one that is displayed in the header text is looking very strange, so i like to remove it.
Does anyone know how this is done ?