How late can I add Maltoferm?

[dirtylarry]

I brewed an extract RIS today and the color came out way too light for the style. It's sitting at brownish right now and I want to get it to black, as it should be. My LHBS stocks maltoferm, but they're closed. Can I add it to the bottling bucket? Or should I add it to primary?

 

[Kayos]

I have seen Sinamar but never heard of Maltoferm. If it's the same it can be used post fermentation and that's actually what it's for.