Before upgrading to Yosemite, I'd like to backup app icons from Mavericks, as the new icons are so ugly.
What's the best way to keep a full copy of old system icons from Mavericks?
UPDATE:
Finally, I do it one by one using Yuki Yamashina's method.
Best Answer
Following @ohho's answer, I wrote a quick script that will save you the effort of adjusting the colour of each icon. This script handles Dropbox folder icons too. You will need imagemagick and xcode command line utilities installed. The best way to get both is to install homebrew and then run
Here is the script. I chose to reduce saturation by -20% and adjust the hue to make the colour less green and more blue.
Save this as say '~/folder_colour_adjuster.sh' and then run
Restart your mac and enjoy: