Organize Nail Polish by Color, Brand, or Finish?

Every collector hits this question: do I line them up by color, group them by brand, or sort by finish? They are not equally good, each one answers a different question, and the right pick depends on how you actually reach for polish.
By color
The prettiest and most intuitive. You almost always shop your own shelf by mood, “I want a deep red tonight”, so a rainbow layout matches how your brain searches. The weakness: shades that sit between families (is that a coral or a pink?) end up wherever you guessed, and big collections need sub-sorting within each color.
By brand
Tidy if you are loyal to a few brands or you swatch and review. It makes restocking and spotting gaps in a line easy. But it is the worst for actually choosing a color to wear, nobody thinks “I feel like an OPI today,” they think of a shade.
By finish
Underrated for big collections. Keeping cremes, shimmers, glitters, holos and magnetics in their own zones matches how you often decide, “something sparkly” or “a clean creme.” If finishes are new to you, here is what each finish means.
A physical shelf forces one axis
A drawer or rack can only be sorted one way at a time. Pick color and you lose easy brand grouping. Pick brand and you lose the at-a-glance color shop. For most people, color wins on a physical shelf because it matches how you choose. But you are always giving something up. (House Digest rounds up shelf and rack setups if you want ideas.)
A catalog lets you stop choosing
This is where a digital list beats any shelf: it holds all three axes at once. Sort the drawer by color for the looks, and let an app filter the same collection by brand when you are restocking, or by finish when you want sparkle, or by color family when you are matching an outfit. You are not locked into one system, you switch the view to fit the question. (A full method for that in organizing without a spreadsheet.)
Further reading: storing and organizing nail polish (Life with Less Mess).