It does make sense if you live in a tropical country where birds have more that one color...
My confusion arise from the fact the "De" (The) is us in the sentence. Why it is use if we have "Flagarna" (The birds)? This is what make me think the sentence was about the color of the bird and not about the bird itself.
The article is needed before adjective + determinate noun.
I'd translate I like the yellow of the birds as Jag tycker om fåglarnas gula färg or Jag tycker om den gula färgen på fåglarna. If you try to say that without adding the word färg 'color' in Swedish, it will sound very poetic/archaic.
after reading all these comments i am still confused about the de article before an adjective. are there just certain adjectives/nouns that require it beforehand and i just have to learn them (if which is the case, which is it gula or fåglarna that requires is) or is there a way to predict that the sentence will have this random DE in it.?
If you're speaking about something determinate, with an adjective, you normally need to have an article first. (the only exception is things that are names or more or less like names, like Vita huset, 'the White house')
So whenever you have the + adjective + noun in English, it will be de/den/det + adjective + determinate noun in Swedish.