"niyang" (niya'ng) is a contraction of "niya na" used to show possesion (possesive noun): "ang itim niya na (niya'ng) sapatos.' ("his/her black shoes.") "ang mabait niya'ng aso." ("his/her kind dog.") sometimes, you'll likely to hear "kaniya'ng (kaniya na) in contemporary tagalog: "ang kaniya'ng itim na sapatos." ("his/her black shoes.") "ang kaniya'ng mabait na aso." ("his/her knid dog.") did you notice the difference? (note: more often than not, in writing tagalog sentences, we disregard the apostrophe mark and write it as spelled.) "blues niya'ng itim." could just be a punning of "blusa niya'ng itim" ("his/her black graduation gown/robe") - commonly seen worn by graduating student. :)

howdy! can you please put additional details cause the word can be use in different way. cowboy...