Они наверное хотят классы.
Я сделал так:
В настройках темы во вкладке Пользовательские CSS вставить код
.btn-primary {background-color:#009678;border-color:#009678}
.btn-primary:hover {background-image: linear-gradient(to bottom, #09a283, #01866b);background-image:#00785a;border-color:#00785a}
.btn-primary:active {background-image: linear-gradient(to bottom, #01866b, #01866b);background-color:#094f40;border-color:#094f40}
.btn-primary:not(:disabled):not(.disabled):active {background-color:#00785a;border-color:#00785a}
.btn-primary.focus,.btn-primary:focus {box-shadow: 0 0 0 0.2rem rgba(0,150,120,.5) !important}
.btn-primary:disabled {background-color:#009678;border-color:#009678}
.btn-danger {background-color:#e6a446;border-color:#e6a446}
.btn-danger:hover {background-image: linear-gradient(to bottom, #f7ae47, #da9839);background-color:#d29032;border-color:#d29032}
.btn-danger:active {background-image: linear-gradient(to bottom, #da9839, #da9839);background-color:#e6a446;border-color:#e6a446}
.btn-danger:not(:disabled):not(.disabled):active {background-color:#c88628;border-color:#c88628}
.btn-danger.focus,.btn-danger:focus {box-shadow: 0 0 0 0.2rem rgba(230,164,70,.5) !important}
Соответственно цвета меняем на свои