Getting SASS error when creating new theme

I tried creating a new theme

@import '@angular/material/core/theming/all-theme';

// Include non-theme styles for core.
@include md-core();

// Define a theme.
$primary: md-palette($md-light-blue);
$accent:  md-palette($md-teal, A200, A100, A400);

$theme: md-light-theme($primary, $accent);

// Include all theme styles for the components.
@include angular-material-theme($theme);

It is throwing the following error

home.style.css:8Uncaught Error: Module build failed: 
undefined
              ^
      Argument `$color` of `opacity($color)` must be a color

Backtrace:
    node_modules/@angular/material/core/theming/_theming.scss:55, in function `opacity`
    node_modules/@angular/material/core/theming/_theming.scss:55, in function `if`
    node_modules/@angular/material/core/theming/_theming.scss:55, in function `md-color`
    node_modules/@angular/material/core/theming/_theming.scss:51, in function `md-color`
    node_modules/@angular/material/core/ripple/_ripple.scss:68, in mixin `md-ripple-theme`
    node_modules/@angular/material/core/_core.scss:26, in mixin `md-core-theme`
    node_modules/@angular/material/core/theming/_all-theme.scss:26, in mixin `angular-material-theme`

It is working fine after commenting @include md-core-theme($theme) in _all-theme.scss. But i am not sure it breaks something else.

[mattiLeBlanc]

I had a similar issue, which occurred because when I apply the color, I forgot to use mat-color.

@import '../../../../node_modules/@angular/material/_theming';
@include mat-core();

$podshark-light-primary: mat-palette($mat-grey, A100,A100,A100); //white
$podshark-light-accent:  mat-palette($mat-pink, A200, A100, A400);
$podshark-light-warn:    mat-palette($mat-red);

$custom-theme: mat-light-theme( $podshark-light-primary, $podshark-light-accent, $podshark-light-warn);

@mixin mat-form-field($theme ) {

  $primary: map-get( $theme, primary);
  $warn: map-get($theme, warn);

  mat-form-field {
    .mat-form-field-underline {
      background-color: $primary; // -> THIS IS WRONG!
      background-color: mat-color($primary); // -> THIS IS RIGHT :)
    }
    .mat-form-field-placeholder {
      color: mat-color($primary);
    }
  }
}

@mixin custom-theme( $theme ) {
  @include mat-form-field( $theme );
}

[guysenpai]

I have the same issue