PNG ICO ICNS MORE
Computer & hardware
Smooth
Crystal Project
messagebox, Info
WhiteSmoke
256x256
Futurosoft
Info
DarkSlateBlue
128x128
Network & communications
Oxygen
Info, user, person
CornflowerBlue
Kgpg, Info
Gainsboro
48x48
UI
Function icons
Error, warning, Info
DarkRed
16x16
Mixed
Carpelinx
DarkGray
Desktop apps
KDE Crystal Diamond
Black
Info, messagebox
22x22