If you just want that bit of paint ... different colour ... discontinued line of varnish etc, chances are Sam will have it. This shop is crammed with aisles full of mistints and small runs of paint in all the colours of the rainbow. I think they used some on the outside of the shop, it's an orangey colour and you can't miss it along the road in Yarraville, set back a little from the street. Park in the side street (Burns St).
I came in here looking for just a small amount of enamel paint for an outside fixture - rather than paying a huge amount for new paint and having tons left over I didn't need. I was able to get a tin of just what I wanted in a dark base (usually more expensive) to paint my item with for a fraction of a cost of the normal new-paint stores. You never know what you're going to find. All a real bargain, half price or more. Be prepared to look around for a while. And very helpful chatty staff.
Also have painters' supplies. A really handy renovator or odd-job person's shop.
Approximate cost: $15