Hey there,

There is no setting to do that currently.

But you can add the following custom CSS code into EasyBlog > Themes > Custom CSS:

body #eb .btn-default {

    color: #FFD700 !important;

    background: #FFD700 !important;

}

Take note that you need to change the color code that you want.

Also, take note that 'color' is for text color and 'background' is for background color.

Do clear all your cache before you see the changes.

Can you have a try and see how it goes?