For Merveillesians who want an ImageMagick one-liner to replace the white in their avatar with orange for October:

convert avatar.gif -fill '#ff8800ff' -opaque '#ffffffff' avatar-october.gif

@chorist Now I just need a command to come up with an imaginative display name! I forgot about that aspect and now I'm deer-in-headlights with all the snappy screennames such as yours!