1) When the adjective is in front of the noun it has to agree with gender, case, and number. "Wolf" in this sentence = masculine, nominative, singular.
2) The adjective is preceded by an indefinite article (an "ein" word), therefor it gets "mixed inflection" endings seen here: http://en.wikipedia.org/wiki/German_declension#Mixed_inflection.5B6.5D
3) If the sentence was "A wolf is red", the German would be "Ein Wolf ist rot" as "rot" is after the noun.
Hope that helps!
In the given link, an example for Masculine Genitive is "meines grünen Tees". Why not "meines grüneS Tees"? From the Genitive on, some differences between the ending of colours and pronouns begin to appear.
"Ein Roter lauf." - pronunciation is so bad,. My husband speaks German and he hears the same incoherent phrase. Maybe this is an example of Yanni/Laurel?