It's often difficult to answer usage questions out of content, but as far as I know, yes, ribbon is always used as a noun. A good way to check if a word is a noun is to put the word "The" in front of it and then try to use it in a sentence. For example: The ribbon was green. See, the sentence makes sense using "Ribbon" as a noun. We can even switch the words of the sentence around (as long as we keep "The" and "Ribbon" together) and the sentence should still sound correct.
Green was the ribbon.
Was the ribbon green?
Don't the sentences still sound right? So "Ribbon" should be a noun. I hope this helps!