Abilityilla ei ole väriä, mutta niiden sourceilla on. Protection from black estää targetoimasta abilityilla, joiden sourcet ovat mustia, joten Shriekmawin ability ei toimi protection from blackin omaaviin creatureihin.
502.7b. A permanent or player with protection can't be targeted by spells with the stated quality and can't be targeted by abilities from a source with the stated quality.
~jari