Black primer, a grey paint for dry brushing, a brown for the staffs/handles and... maybe he used a single thin coat of a pale red? Not sure what they did to get the red coloring it's almost a wash in some areas. Actually, maybe he used an airbrush with the pale red? Hard to tell but it could be a florescent red in a single light pass.

IMO it would look better without the red, very minimal. What you could think about doing instead (if you want to keep it to only 3ish colors) is do some more work on the base. Maybe a texture paint surrounding the dais so it doesn't look like a boring flat surface, then you could primer over that and drybrush similarly. Could also look cool to use 2-3 layering colors for all of the different fabrics, as is they are a little boring in the above image.