@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 + 0.055) / 1.055;
      $value: powerNumber($value, 2);
    }

    $color-rgb: map-merge($color-rgb, ($name: $value));
  }

  @return map-get($color-rgb, "red") * 0.2126 + map-get($color-rgb, "green") * 0.7152 + map-get($color-rgb, "blue") * 0.0722;
}

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