Is Shade A1 Going to Be Noticeably White?

A1 shade is a shade at the top end of the international shade guide for tooth colors.  A1 used to be considered a very white shade but with all the bleaching shades now, there are even whiter shades yet.  If you plan to whiten your teeth, the teeth may actually bleach whiter than an A1 and then your crowns might look yellow compared to the rest of your teeth.  B1 is actually a little bit lighter than A1.  If you plan to bleach, then I would bleach and let your color settle for a couple of weeks.  Then have your dentist take an exact shade match to your teeth.  You may need to bleach periodically to maintain the exact color of your natural teeth.  Porcelain never bleaches so it must be matched carefully to your natural teeth.  Good luck!

Shade A-1 is nice white shade, but more important question here should be that if your other front teeth are close to shade A-1? If you like shade A-1, you should whiten rest of the teeth first to try to get them to A-1. Your new crowns made in shade A-1 will blend in beautifully after teeth whitening and will not be noticeable.
Hope this makes sense. Good Luck!