
Hi Sophia,
Lemon dalmatians aren't very common (in 30 years in the breed I have never seen one!), and as it is a breed fault no reputable breeder breeds them on purpose. They do occasionally turn up in litters, and are (or should be) sold as mismarks who should not be bred from. If you happen to come across one, beware if the breeder tries to tell you it is a more valuable puppy - they are trying to con you.
As for websites, the
Dalmatian Telegraph has a lot of very useful information.
Far more important than colour is the hearing status of the dalmatian. Beware any breeder who cannot show you copies of the hearing certificate of both dog and bitch (showing bilateral hearing of course!) and who does not have their puppies tested prior to sale.
Hope this helps.
:)