I've just used the final dregs from my last pot of the old GW Bestial Brown on the bases of my Orcs. With the continuing GW price rises and my love of Vajello I was wondering whether Vajello did a compatible colour that I could buy - they do, Beasty Brown!
How do I know? By using this Paint Comparison Chart on the Dakka Dakka forum which should be very useful (unless you use Foundry paints!).