The Company Couple after a painting by Aelbert Cuyp   How good at painting black the old Dutch masters were, a black of depth and richness that clad those burghers and their wives so soberly enjoying their new wealth. Yet one wonders—did they really wear those clothes in their far-flung colonies? Close-fitting, black, snowy white collars, even pleated ruffs, hardly tropical kit, or were their portraits, mostly painted at home, more a formal presentation of status and fortune?   That portly couple Cuyp has painted, a senior merchant of the Dutch East India Company, is shown with his wife, both…