PNG ICO ICNS MORE
Farm-Fresh Web
wrong, exclamation, Computer
LightSteelBlue
32x32
exclamation, Error, warning
Silk
exclamation, table, Error
16x16
Error, wrong, warning
pic, exclamation, photo
phone, Alert, exclamation
Function
Error, warning, Alert
48x48
UI
Pixel
Fugue Icons
exclamation, Folder, Blue