Henry Morgan is attested to have flown Red Ensign and Saint George flag as expectable, likely accompanied by the Budgee jack and pennant that would identify him as a privateer.
Otherwise, it is actually doubtful that Henry Morgan ever flew a red Jolly Roger as some modern media suggest, but not so unlikely that he could have used a plain red one instead; for this was widely known by Caribbean buccaneers –and Morgan hired a number of them indeed for some of his campaigns. Anyway, I've thought it colourful to add a red Jolly Roger mast flag to this set, despite the unlikeliness of its eventual usage.
Sources: W. G. Perrin, «British flags», Cambridge 1922 | Benerson Little, «How History's Greatest Pirates Pillaged, Plundered, and Got Away With It», Beverly (MA) 2010
Sizes: ensign W12 x L18 mm, mast flags W8 x L12 mm, jack W6 x L9 mm, pennant W4 x L48 mm.