It's only because diferent coloured hyacinths may grow at different rates, so you could end up with one in bud, one full out and one finished. The same named varieties will probably all flower at the same time.

It's only a matter of taste, I think. Some people may not like the look of a mulitcoloured mixture? If you want to, go for it! :-)

when buying your bulbs ake sure you get the that flower at the same tie. soe are early and some late.

I would have guessed that people can prefer not to kix colours.

We all have our own preferences.

Mix them if you wish.