I Want The Classic IntelliJ IDEA Application Icon Back.
Or specify a custom icon in IDEA_HOME\bin\idea.properties
Unix: "classic.icon=/path/to/my/icon.png"
Windows : "classic.icon=c:\\path\\to\\icon.png" (use two '\' as file separator)
Supported products

AppCode

CLion

DataGrip

IntelliJ IDEA

PhpStorm

PyCharm

Rider

RubyMine

WebStorm
Recent change notes
macOS support.