Comment 3 for bug 563362

The reason the folder-video icon and folder-image was given purple , is to keep some consistency for the folder icons, the user desktop turned purple and it was the lone purple icon there in a sea of orange.
Purple is being used mainly for the desktop[computer / monitor] icons.

Using an orange film on an orange folder is not ideal too ;-) , some other color needed to be used for the film.
The folder-video icon was "inconsistently" grey earlier too ;p

None of the MIME or any other icons use purple. However it is something to be considered for Maverick. Not sure we would end up doing it.