Machines + Surprising Graffiti

I drove past a railway depot and took these pictures from the street with a long lens.

A diesel locomotive for the maintenance machinery

Water was being sprayed on the gravel ballast is made of.

"Saattaen vaihdettava" is a phrase painted on countless pieces of rolling stock. It means that that particular piece of non-locomotive rolling stock must remain connected to a locomotive until any shunting(UK, Aus)/switching (US) operation is completed.

How on Earth did they spray paint those texts? Or were they painted with regular paint?