Its probably not a secret anymore due to the sheer amount of times I use this palette in my looks and how many times I mention it that its my absolute favourite palette. Its undoubtedly the Guerlain Ombre Eclat in 407 Bal de Minuit.
I was looking at swatches of Lavshuca’s summer collection and I noticed that BR-1 is a really good, and inexpensive dupe for this palette. If you missed out on the Guerlain or if you liked it but didn’t want to spend $60+ on it, the Lavshuca is a good alternative. If you wanted something similar but not as intense/smokey, then BE-1 is another good alternative.
[Update] Thank you to Blair for pointing out that its from the summer, not spring collection. Ooops =/