@function mergeColorMaps($bulma-colors, $custom-colors) {
  // we return at least bulma hardcoded colors
  $merged-colors: $bulma-colors;

  // we want a map as input
  @if type-of($custom-colors) == 'map' {
    @each $name, $components in $custom-colors {
      // color name should be a string and colors pair a list with at least one element
      @if type-of($name) == 'string' and (type-of($components) == 'list' or type-of($components) == 'color') and length($components) >= 1 {
        $color-base: null;

        // the param can either be a single color
        // or a list of 2 colors
        @if type-of($components) == 'color' {
          $color-base: $components;
        }
        @else if type-of($components) == 'list' {
          $color-base: nth($components, 1);
        }

        $color-invert: null;
        // is an inverted color provided in the list
        @if length($components) > 1 {
          $color-invert: nth($components, 2);
        }

        // we only want a color as base color
        @if type-of($color-base) == 'color' {
          // if inverted color is not provided or is not a color we compute it
          @if type-of($color-invert) != 'color' {
            $color-invert: findColorInvert($color-base);
          }
          // we merge this colors elements as map with bulma colors (we can override them this way, no multiple definition for the same name)
          $merged-colors: map_merge($merged-colors, ($name: ($color-base, $color-invert)));
        }
    }
    }
    }

  @return $merged-colors;
}

@function powerNumber($number, $exp) {
  $value: 1;
  @if $exp > 0 {
    @for $i from 1 through $exp {
      $value: $value * $number;
    }
  }
  @else if $exp < 0 {
    @for $i from 1 through -$exp {
      $value: $value / $number;
    }
  }
  @return $value;
}

@function colorLuminance($color) {
    $color-rgb: ('red': red($color),'green': green($color),'blue': blue($color));
    @each $name, $value in $color-rgb {
        $adjusted: 0;
        $value: $value / 255;
        @if $value < 0.03928 {
            $value: $value / 12.92;
        }
        @else {
            $value: ($value + .055) / 1.055;
            $value: powerNumber($value, 2);
            $color-rgb: map-merge($color-rgb, ($name: $value));
        }
    }
    @return (map-get($color-rgb, 'red') * .2126) + (map-get($color-rgb, 'green') * .7152) + (map-get($color-rgb, 'blue') * .0722);
}

@function findColorInvert($color) {
  @if colorLuminance($color) > 0.55 {
    @return rgba(#000, 0.7);
  }
  @else {
    @return #fff;
  }
}