Is a broccoli that already turned yellow anyhow harmful? After I bought a broccoli I placed it into my fridge. Today I rediscovered it and wanted to eat it. Now the crown of the broccoli already turned yellowish (it's actually a yellowish-greenish-brownish color).

Is it still safe to eat the broccoli (after cooking) or are there any health harming issues I should consider before eating?
It is safe to eat, but it would be fibrous and a bit tough - not to mention that the flavor might be a bit subdued. I would personally cut my loses and toss it in the bin.