How do I change the color of a button?

Hello. How do I change the color of a button? For some reason, the buttons became lighter.

Everything seems to be correct in the settings.

mark256
Hi
Here is code used by button you can override in custom css

.readmore .btn {
    background-color: #e9ecef;
}

I am not sure the path as the site is using high compression from JCH.

Hello. Thanks