Repainting garden furniture this year, picked a colour and decided I want to go slightly darker. Previously adding a few little tester posts in various combinations, I have managed to get the right colour.
However this year I got 'grey slate' which looks more mid blue/grey than the grey slate on the tin. I've added 4 little tester pots and it just won't darken.
Any ideas without forking out for another new pot of paint and waste what I already have?
TIA