The central 'yellow' plant is just one rosett of the plant in the left-hand corner. If it flowered this summer then the flowering rosett will die as it is monocarpic. The rosetts surrounding it keep the plant going. However, this yellow rosset does not look as if it has flowered so it is difficult to say. If it goes brown and is obviously dead then just cut it out, without disturbing the 'babies' and put a bit of grit in the hole.
Nice looking trough.

It's a beautiful colour! Enjoy it! Sempervivums do change colour throughout the year, the rosette looks healthy enough to me, just a pretty autumnal colour, you've got plenty of babies anyway to replace it if it dies.