Blue Spot Marking Paint. The spot marking choice of many industries for marking out! Signet upside down spot marking paint comes in a big, easy to use 350gm aerosol with a choice of 15 colors. Available as a single can, or box lots with 12 cans per box. Colour - Blue - Colour - Red - also availiable in black, red, green, yellow, white, orange, purple, fluro red, fluro blue, fluro orange, fluro pink, fluro green, fluro yellow, fluro purple.