How to change icon color in Sublime Text 3 theme?

Question

Sublime Text

Recently I decided to try to write a theme for Sublime Text 3, and I had a question:
How to change the color of icons in a theme?

{
  "extends": "DAneo Origin.hidden-theme",
  "variables": {
    "bg":"#3d3f43",

  ////// Main Settings /////////////////////////////////////////////////////////

    "font_face": "system",
    "font_size": 12,
    "font_size-small": 3,
    "font_size-tiny": 9,

    "accent": "var(--accent)",

    // Version Control State Colors

    "vcs_added": "var(--greenish)",
    "vcs_added_modified": "var(--orangish)",
    "vcs_deleted": "var(--redish)",
    "vcs_modified": "var(--orangish)",
    "vcs_staged": "var(--yellowish)",
    "vcs_staged_modified": "var(--orangish)",
    "vcs_unmerged": "var(--redish)",
    "vcs_untracked": "grey",

  ////// Button Controls ///////////////////////////////////////////////////////

    "button_font_face": "var(font_face)",
    "button_font_size": "var(font_size)",

  ////// Side Bar //////////////////////////////////////////////////////////////

    // Headings Text

    "sidebar_heading_font_face": "var(font_face)",
    "sidebar_heading_font_size": "var(font_size)",
    "sidebar_heading_font_bold": false,
    "sidebar_heading_font_italic": false,

    // Tree Items Text

    "sidebar_font_face": "var(font_face)",
    "sidebar_font_size": "var(font_size)",

    "sidebar_folder_icon_tint-collapsed-dark": "color(var(--yellowish) alpha(0.8))",
    "sidebar_folder_icon_tint-collapsed-light": "var(--yellowish)",
    "sidebar_folder_icon_tint-expanded-dark": "var(accent)",
    "sidebar_folder_icon_tint-expanded-light": "var(accent)",

  ////// Tabs //////////////////////////////////////////////////////////////////

    "tab_font_face": "var(font_face)",
    "tab_font_size": "var(font_size)",

  ////// Grid Layout ///////////////////////////////////////////////////////////

    "grid_border_size": 1,

  ////// Quick Panels //////////////////////////////////////////////////////////

    "quick_panel_text_font_face": "var(font_face)",
    "quick_panel_text_font_size": "var(font_size)",

    "quick_panel_details_font_face": "var(quick_panel_text_font_face)",
    "quick_panel_details_font_size": "var(font_size-tiny)",
    "quick_panel_details_font_italic": true,

  ////// Tooltips //////////////////////////////////////////////////////////////

    "tooltip_font_face": "var(font_face)",
    "tooltip_font_size": "var(font_size)",

  ////// Status Bar ////////////////////////////////////////////////////////////

    "statusbar_font_face": "var(font_face)",
    "statusbar_font_size": "var(font_size)",

    // VCS annotation

    "statusbar_vcs_font_face": "var(statusbar_font_face)",
    "statusbar_vcs_font_size": "var(font_size-small)"
  },
  "rules": []
}

Just in case icons.


PS Theme based on DANEO.