I'm weird - I have all my florals in one section, no matter what the main color is - if it's floral, it's there.
All of my novelty fabrics are sorted by theme.
All of my colored fabrics are sorted by color.
I know I'm an oddball. I just like to keep my florals separated since I'm not a big floral person - which is funny since I have a ton of them. I tend to use them as backings for things that people won't see like wall hangings and table runners lol. I just don't like those old fashioned or girlie girl florals much.