Resolved: Invalid regular expression: invalid escape

dateFormats: {
    // tslint:disable-next-line:max-line-length
    title: `Date Formats (Used for all Date Instances) <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toLocaleDateString#Parameters" target="_blank" rel="noopener">Parameter Reference</a>`,
    // tslint:disable-next-line:max-line-length
    description: `Use Default Template as starter. No spaces or line-breaks. Wrap all "keys" and "values" in double-quotes. Partial definition is allowed, override only what needs to change. `,
    type: 'string',
    pattern: `\\{.*\\:\\{.*\\:.*\\}\\}` // The offending regex
  },

    pattern: `\\{.*:\\{.*:.*\\}\\}` // The offending regex