Hi Rapido,
Yo can use the below example if you want to change all the default buttons active behavior;
.btn:active, .mx-button:active, .btn-default:active, .btn-primary:active {
background-color: #002412;
border-color: #002412;
color: #FFFFFF;
}
or if you want to change a specific button then you can add custom class (for example btn-arrow) on that button and then style it in your css as shown in the example below;
.btn-arrow:active {
background: #ccf0dd;
color: black;
}
Hope this helps!