Overseas paint matching is a breeze. You grab a few paint sample cards that look right then you find the right one when you get home and compare to your wall.
But they don't have the cards here anywhere I have looked, just fold out brochures that have a fraction of the possible colors.
How can you match? Chisel out a chunk of wall and take it to Homepro and match it with the single sample book they have on hand?