How to configure color of callouts in PDF format

[nichtich]

Description

Callouts don't mention configuration of their color but HTML based export formats support SASS variables for callout colors. How to change colors in PDF format? It looks like the default colors are defined in two places (code duplication?) without being able to override with configuration parameters:

• src/resources/filters/common/colors.lua
• src/resources/filters/modules/constants.lua

[nichtich]

It turns out, include-in-header does not work because the default colors are set afterward. But include-before-body does:

format:
  pdf:
    include-before-body:
      - text: |
          \definecolor{quarto-callout-note-color}{HTML}{000000}
          \definecolor{quarto-callout-important-color}{HTML}{000000}
          \definecolor{quarto-callout-warning-color}{HTML}{000000}