Method parseColorGroup

static/katex/katex.mjs:15508–15535

* Parses a color description.

(optional)

  parseColorGroup(optional) {
    const res = this.parseStringGroup("color", optional);

    if (!res) {
      return null;
    }

    const match = /^(#[a-f0-9]{3}|#?[a-f0-9]{6}|[a-z]+)$/i.exec(res.text);

    if (!match) {
      throw new ParseError("Invalid color: '" + res.text + "'", res);
    }

    let color = match[0];

    if (/^[0-9a-f]{6}$/i.test(color)) {
      // We allow a 6-digit HTML color spec without a leading "#".
      // This follows the xcolor package's HTML color model.
      // Predefined color names are all missed by this RegEx pattern.
      color = "#" + color;
    }

    return {
      type: "color-token",
      mode: this.mode,
      color
    };
  }
  /**
   * Parses a size specification, consisting of magnitude and unit.
   */