Slate doesn't look very different from grey except that it is usually darker. The way the gene is inherited is very different. You're not likely to see a slate because they are extremely rareThanks ! Whats the difference between a normal grey & slate ? is slate just a darker shade ? I had no idea she was opaline, her wing markings look regular to me lol ....its so interesting all the amazing colors & mutations in budgies !!!