

This guide will show you how to set up elementary OS completely with Arc theme and Papirus icons. Everything from panel to plank.
First make sure you’re setup for changing themes on elementary OS. This guide will show you how: Howto change theme in elementary os.
Secondly install the Arc theme and Papirus icons on your elementary OS. Open the terminal and copy/paste;
sudo apt install arc-theme papirus-icon-theme
Open elementary Tweak in System Settings and choose the GTK theme and the icon theme you just downloaded. Note: There’s 3 kind of Arc theme, choose the one that fits your desire. The Papirus icons set you have to choose is ePapirus which is specific for elementary OS.
PLANK
Next thing is to install arc theme for Plank. Open the terminal and copy/paste;
mkdir -p ~/.local/share/plank/themes/Arc
cp -r /usr/share/themes/Arc-Darker/plank/dock.theme ~/.local/share/plank/themes/Arc/dock.theme
plank --preferences

WINGPANEL

To get the wingpanel to fit the rest of the theme a little bit of tweak is necessary. Open the terminal and copy/paste;
nano ~/.config/gtk-3.0/gtk.css
Add the following;
/*********************
* wingpanel support *
********************/
.panel {
background-color: rgba(47,55,66,1.0);
transition: all 1s ease-in-out;
}
.panel.maximized {
background-color: rgba(47,55,66,1.0);
}
[ctrl]+[o] = save and [ctrl]+[x] = exit
WALLPAPER
Everyone have different taste in wallpaper but if you like this one head over to System76 and download it here: https://system76.com/swag/desktop-wallpapers
ENABLE DESKTOP AND ADD PLANKS

To do this follow this guide: Howto enable Desktop on elementary OS
APPLICATION MENU

To change the menu to show the icons and in line and rows. You find the guide here: Howto change Slingshot to the old style in elementary OS
ENJOY!!! ^_^
Tested on: elementary OS 5.1.7