On Finder, navigate to the location where you downloaded the .icls and copy it. Then press shift + command + g and go to:
~/Library/Preferences/WebIde80/colors/
Paste the .icls file in and restart your IDE. Then navigate to Settings > Editor > Colors & Fonts and select the color scheme you just added.
On Windows Explorer, select the .icls file just downloaded and copy it. Then navigate to the colors folder, located in: C:/Users/USERNAME/.WebIde80/config/colors Paste the .icls file in and restart your IDE.
Then navigate to File > Settings > Editor > Colors & Fonts and select the color scheme you just added.
On Linux, the color files are located in: ~/.WebIde80/config/colors/ After you put your .icls files, restart your IDE. Then navigate to File > Settings > Editor > Colors & Fonts and select the color scheme you just added.
Author of original color schemes https://github.com/chriskempson/base16