I have made scripts to change the blue accent colour in the Arc theme from Horst3180. With these scripts you can make new arc themes with your personal accent colour.
If you want to create a new Arc theme with your personal colour then follow this tutorial.
If you want to download, what has already been created, then follow the next steps for Linux Mint only (or for cinnamon 3.0/3.2 and GTK 3.18 on other distro’s).
Download the zip file and extract it or use this command in the terminal
git clone https://github.com/erikdubois/arc-theme-colora-collection
You will find two folders cinnamon 3.0 and cinnamon 3.2.
Go to a terminal and type in this command to find out what version you have.
Copy/paste the content of the correct cinnamon version folder in your personal home directory in the hidden folder ~/.themes. Or just use the scripts from the github.
Change with your theme manager.