One flaxseed is not better for you than another. Brown flaxseeds provide the same nutritional benefits as yellow (or golden) ones.
Both brown and golden flaxseeds have plenty of lignans and dietary fiber, and both contain a lot of alpha-linolenic acid. While some people may prefer yellow-colored seed, brown flaxseeds add the same nutrition to your diet as do golden ones. Brown flaxseeds may be more commonly found than golden, as more brown than golden flaxseeds are grown commercially.