Prints were somewhat yellow after processing and some yellowed with age depending on the dye stability of the paper. This varied and improved with each generation of paper. Stable brighteners were not available at that time either.
FB paper absorbed some chemicals and the process chemistry and washes were needed to remove the chemicals from both the baryta and the paper fibres.
Just as today, you see shorter washes with RC B&W, and longer washes with FB B&W, the same is true for color, with the added problem that the chemicals create colors.