[A. G. Maisey]

Nope, looks like I was wrong.

Most generally used language in Sri Lanka is Sinhala, and it looks like adjectives precede nouns in Sinhala, so it would be gal mita piha and vak piha.

Also looks like "piha" is really "pihiya", but in speech the "--iy--" part of the word is not easily heard, it disappears into the "h" and the "a", similar to the way the "e" in "keris" is not heard and the word is heard as "kris".