Passing Xcolor package in YAML markdown for Pandoc

I have the following YAML in a .md file and everything is working smooth.
But I want to use xcolor to change color for TOC.

Pandoc Manual (see here) says:

linkcolor, filecolor, citecolor, urlcolor, toccolor

color for internal links, external links, citation links, linked URLs, and links in table of contents, respectively: uses options allowed by xcolor, including the dvipsnames, svgnames, and x11names lists

My Question is: how do I pass xcolor option / or how to use svgnames color, because if I change
toccolor: Blue to toccolor: DarkBlue I get undefined color.

Error producing PDF.
! Package xcolor Error: Undefined color `DarkBlue'.

See the xcolor package documentation for explanation.
Type  H <return>  for immediate help.

Here is the YAML Code

---
title: Name of the Article
author: Author Name
date: today
lang: ro-RO
geometry:
  - a4paper
  - margin=2.5cm
  - heightrounded
header-includes: |
  usepackage{fancyhdr}
  pagestyle{fancy}
  fancyhead[L]{textbf{leftmark}}
  fancyhead[R]{textbf{rightmark}}
  lfoot{}cfoot{thepage}rfoot{}
numbersections: yes,
linestretch: 1.2
toccolor: Blue
bibliography: [X:/absolute/path/to/ref.bib]
csl: [X:/absolute/path/to/chicago-fullnote-bibliography.csl]
documentclass: article
toc: true
---