Lilac Foil is on my middle fingernail, and Lilac Chameleon on index and ring fingernails
It's really cloudy here at the minute and all my pics are taken in natural light. Whilst the two are similar - the Lilac Chameleon is definitely more grey/silver, less of a purple tone. In some lighting it isn't all that visible, in others you can definitely see the difference. Then again, unless you're doing what I'm doing and comparing, no one will know!
I did check the Barry M website and they do have Lilac Foil listed, but it's out of stock. Who knows whether they'll have more stock available. I did a quick search as well, and did find Lilac Foil on eBay here!
Hope this has been helpful to the person who asked! :D