mdb-ui-kit/scss/includes/mixins/_variations.scss

// variations(unquote(""), background-color, #FFF);
@mixin variations($component, $selector-suffix, $mdb-param-1, $color-default) {
  @include generic-variations($component, $selector-suffix, $color-default, "variations-content", $mdb-param-1);
}

@mixin variations-content($args) {
  //@debug "#{map-get($args, mixin-name)}{ #{map-get($args, material-param-1)}: #{map-get($args, variation-color)}; }";
  //@debug "#{inspect($args)}";
  //@error "break here";
  #{map-get($args, material-param-1)}: map-get($args, variation-color);
}

@mixin background-variations($component, $selector-suffix, $color-default) {
  @include generic-variations($component, $selector-suffix, $color-default, "background-variations-content", null);
}

@mixin background-variations-content($args) {
  background-color: map-get($args, variation-color);
  @if (map-get($args, variation-color) == $mdb-btn-background-color) {
    color: $mdb-text-color-primary;
  } @else {
    color: map-get($args, variation-color-text);
  }
}

// navbar-variations(" label input[type=checkbox]:checked + .toggle:active:after", $brand-primary
//@mixin navbar-variations($component, $selector-suffix, $color-default) {
//  @include generic-variations($component, $selector-suffix, $color-default, "navbar-variations-content", null);
//}
//
//@mixin navbar-variations-content($args){
//  $variation-color: map-get($args, variation-color);
//  $variation-color-text: map-get($args, variation-color-text);
//
//  background-color: $variation-color;
//  color: $variation-color-text;
//  // deeply defined to override welljumbo class without !impotant need
//  .navbar-form .form-group input.form-control,
//  .navbar-form input.form-control {
//    @include material-placeholder {
//      color: $variation-color-text;
//    }
//  }
//  .dropdown-menu {
//    border-radius: $border-radius-base;
//    li > a {
//      font-size: $mdb-dropdown-font-size;
//      padding: 13px 16px;
//      &:hover,
//      &:focus {
//        color: $variation-color;
//        background-color: $grey-200;
//      }
//    }
//    .active > a {
//      &:hover,
//      &:focus {
//        color: $variation-color-text;
//      }
//      background-color: $variation-color;
//      color: $variation-color-text;
//    }
//  }
//}

// interpolation of mixin-name is not allowed evidently, so we statically include based on the mixin-name given
@mixin call-variations-content-mixin($args) {
  $mixin-name: map-get($args, mixin-name);
  @if $mixin-name == variations-content {
    @include variations-content($args);
  } @else if $mixin-name == background-variations-content {
    @include background-variations-content($args);
  } @else if $mixin-name == text-variations-content {
    @include text-variations-content($args);
  } @else if $mixin-name == button-variations-content {
    @include button-variations-content($args);
  } @else if $mixin-name == bg-color-variations-content {
    @include bg-color-variations-content($args);
  } @else if $mixin-name == bg-box-shadow-variations-content {
    @include bg-box-shadow-variations-content($args);
  } @else if $mixin-name == bg-img-variations-content {
    @include bg-img-variations-content($args);
  } @else if $mixin-name == navbar-variations-content {
    @include navbar-variations-content($args);
  }@else if $mixin-name == alert-variations-content {
    @include alert-variations-content($args);
  } @else {
    @error "Unknown mixin: #{$mixin-name}"
  }
}

//
// To use this mixin you should pass a function as final parameter to define
// the style. In that definition you can use the following variables to define it.
//
// $variation-color-name ---> "red", "green", "indigo" ...
// $variation-color-full-name ---> "red", "green-50", "indigo-400" ...
// $variation-color ---> #f44336, #e8f5e9, #5c6bc0 ...
// $variation-color-text ---> rgba(255,255,255,0.84), rgba(0,0,0,0.84), rgba(255,255,255,0.84) ...
//

@mixin generic-variations($component, $selector-suffix, $color-default, $mixin-name, $mdb-param-1) {

  //setup map to pass parameters (instead of the incredibly long-error-prone list for each and every @include)
  $args: (
          //extra: $selector-suffix,
          //default: $color-default,
          mixin-name: $mixin-name,
          material-param-1: $mdb-param-1
  );

  // bootstrap styles
  &#{$component}-default#{$selector-suffix} {

    $args-extra: map-merge($args, (
            variation-color: $color-default,
            variation-color-text: $mdb-text-color-light
    ));
    @include call-variations-content-mixin($args-extra);
  }
  &#{$component}-inverse#{$selector-suffix} {
    $args-inverse: map-merge($args, (
            variation-color: $mdb-brand-inverse,
            variation-color-text: contrast-color($mdb-brand-inverse, $mdb-text-color-primary, $mdb-text-color-light)
    ));
    @include call-variations-content-mixin($args-inverse);
  }
  &#{$component}-primary#{$selector-suffix} {
    $args-primary: map-merge($args, (
            variation-color: $brand-primary,
            variation-color-text: $mdb-text-color-light
    ));
    @include call-variations-content-mixin($args-primary);
  }
  &#{$component}-success#{$selector-suffix} {
    $args-success: map-merge($args, (
            variation-color: $brand-success,
            variation-color-text: $mdb-text-color-light
    ));
    @include call-variations-content-mixin($args-success);
  }
  &#{$component}-info#{$selector-suffix} {
    $args-info: map-merge($args, (
            variation-color: $brand-info,
            variation-color-text: $mdb-text-color-light
    ));
    @include call-variations-content-mixin($args-info);
  }
  &#{$component}-warning#{$selector-suffix} {
    $args-warning: map-merge($args, (
            variation-color: $brand-warning,
            variation-color-text: $mdb-text-color-light
    ));
    @include call-variations-content-mixin($args-warning);
  }
  &#{$component}-danger#{$selector-suffix} {
    $args-danger: map-merge($args, (
            variation-color: $brand-danger,
            variation-color-text: $mdb-text-color-light
    ));
    @include call-variations-content-mixin($args-danger);
  }
}