Yes and no. It's really dependent upon the individual fish. You may need to take some steps to make a more successful attempt. I'd buy a blue that is as large or even a little larger than the yellow. I'm betting that the yellow isn't going to take to the newcomer without some aggression. You can also try rearranging your rock work when you add the new fish to throw the yellow out of his "territory" and let them both reestablish at the same time. I have a blue, yellow, purple and naso all together in a 180 so, yes, it can be done. That being said, some fish just won't live together and you should be ready to evict one of them to a new home if you need to. Good luck!