To simplify (I'm a notorious over-simplifier, so please correct me if I'm wrong) I would say that you can spread coffee grounds on your lawn, but don't expect them to green it up until maybe mid- to late-summer when the grounds have decomposed enough to release their nitrogen.
If you consistently top dress your lawn and beds with coffee grounds, they will eventually improve your soil and reduce the need for fertilizer. But don't expect immediate results. A better result will be had from spreading on compost made with coffee grounds, but still not a quick result as the nitrogen is slow-release.
I wonder if you started the coffee grounds top dressing in the fall it would compost over the winter (slowly in cold weather) and release when the weather warmed up in the spring?
