Most stone suppliers group granite colors from 1-5, "group 1" being the least expensive and "group 5" being most expensive.
Each group represents a price category only. The groups are determined by how available a stone is in the market, somewhat similar to how gemstones are priced.
Don't let the # 1 scare you, it has nothing to do with the quality of the stone. In fact, sometimes the lower priced granites are the best quality stones.
Below is a picture from our portfolio of a "group 1" granite called Giallo Ornamental.
Note: Please keep in mind prices vary drastically in different areas of the country, per supplier and per fabricator.
For example: Giallo Ornamental is a "group 1" granite here in Utah when you buy from us. I've heard in other parts of the country it's as high as a "group 4". Please understand I just talk about pricing that is applicable in our market here in Utah.