This is precisely why provenance back to the wild becomes so important with most cichlids. There are numerous brasiliensis-types, and if this fish is as solid yellow as you state, then it's one that I have never seen before, nor is it shown in Weidner's book, which is pretty much the bible on SA eartheaters. Many of these fish get lumped together, and many are still undescribed. Unless the LFS that you purchased it at can come up with more info for you I suspect it will remain a brasiliensis-type, and that's about as close as you're going to get as far as an accurate ID.