"Golden-green" is a good descriptor for the Layla polish. I have put it over a more neutral green base in the past and it does well. Swatch And Learn is noticeably more yellow, as is very clear in the swatch. It's another one of those that I categorize in my head as a "funky green" - mostly because of the yellow, but also it's the way it shimmers around to to several other colors. It's not flattering on me by itself because it's so yellow, so obviously I need to experiment around some more with layering it over something, just like I did with the Layla polish. (Here's S&L's own blog entry about her polish, which gives a lot more details about how they came up with this.)
We have now finished up my folder of photos labeled "green" and now we're on the "yellow-green" folder. I have no actual yellow polishes of any kind so instead of yellow I'll do golds next. I actually have quite a few golds, and I'll probably throw some other metallics in with that. Then we only have orange to get all the way around the wheel once, although I didn't do the reds in the same format I did everything else, so I'll probably go back at the end and re-do those. But before that I'll do the other things that don't quite fit into the color-wheel progression, like browns and grays and so forth. And top-coats - I still have a lot of polishes to go!
Added: I forgot to talk about availability. CE61 is listed on Color4Nails, but it's out of stock. Layla is an Italian brand and its US availability has always been spotty. Here's the Italian website if you want to attempt to navigate around. Swatch And Learn is still available from Pretty Serious - they are an Australian brand but they have a really good US pipeline, and unless things have changed in the last six weeks or so since I last got anything from them, they are quite fast and reliable. (As ever, nobody's paying/compensating me, but I'm a big Pretty Serious fan and I order from them quite regularly.)
Added (2): I stumbled on some more Layla at FabulouStreet - they have several CE polishes but not this one. They do have a fairly large number of Layla polishes from several different lines, though, so I thought that was worth mentioning.