The main background color that is used in most of the places is #002B36.

Starting based on Zorin Green theme, customized to my liking (colors, shadows, roundness) and ZorinGreen-SolDark_Lighter0 remains my preferred choice for the last months, at least.

Such a theme must exists in ~/.themes directory:
cp -r dot_themes/ZorinGreen-SolDark_Lighter0 ~/.themes/

Set on Appearance (this screenshot includes also the window shadow and some part of the wallpaper):

Using Material Black Pistachio Suru flavor for icons.

Saved here in dot_icons directory, and this needs to exist on ~/.icons directory. So:
cp dot_icons/Material-Black-Pistachio-Suru ~/.icons/

Set on Appearance:

The cursor theme is Volantes Light Cursors.

Saved here in dot_icons directory, this needs to exists on ~/.icons directory. So:
cp -r dot_icons/volantes_light_cursors ~/.icons/

Set on Mouse and Touchpad:

The wallpaper used is solarized-golang_std_bg.png. Stored here in wallpapers directory.

Set in Desktop:

Also, for a complete user experience, included some IDEs customizations to the current design/setup.

Saved in ./IDEs/vscode:

• settings.json file that includes the my customizations to the existing Community Material Theme
• keybindings.json file that has my currently preferred shortcuts (that mostly mimick the previous macOS experience)

This section includes additional XFCE specific settings.

I am using a vertical panel: in Panel Preferences, set "mode: Deskbar".
Besides this, a couple of CSS driven customizations were added to ~/.config/gtk-3.0/gtk.css file:

#xfce4-notification-plugin * { -gtk-icon-transform: scale(.6); }

#xfce4-power-manager-plugin * { -gtk-icon-transform: scale(.6); }

#pulseaudio-button * { -gtk-icon-transform: scale(.6); }

#clock-button { font-family: "Antonio"; font-size: 19px; color: #60e6b1 }

/* TBD: Although works on another Xubuntu, on the desktop the bottom line is still present.
tasklist button:checked {
  border: 0px;
  border-right: 1px solid #52c498;
}
*/

/* Alt+Tab window (but I don't think it's working) */
#xfwm-tabwin {
   -XfwmTabwinWidget-icon-size: 96px;
   -XfwmTabwinWidget-preview-size: 64px;
}