Yosemite-icons

These are the software I use frequently,to Yosemite and updates.
Download from here:
https://github.com/kelvinlee/Yosemite-icons

To install icons easily on Yosemite.

Open the icns file and click Edit > Copy
Right click on the .app (for example QQ.app) and click "Get Info". (Or click the app and Cmd+I)
Click on the icon at the top and it will be outlined, when it is outlined simply hit cmd + v - should see the icon change.
Open up terminal and type: killall Dock (Or you can remove the app from the dock and drag it back).
All icons are updated in the dock.