.shopify-payment-button__button--unbranded, .button--success {
    background-color:#83ae42 !important;
    color: #ffffff !important;
}
.shopify-payment-button__button--unbranded:hover, .shopify-payment-button__button--unbranded:focus, .button--success:hover, .button--success:focus{
    background-color: #6e9337 !important;
    color: #ffffff !important;
}