Should you organize books by color?
Yes, if color is how you enjoy and remember the shelves. No, if it keeps hiding books you need to find.
A home library has to work as part of a room, not only as an information system.
Why people like color-organized shelves
Color creates an immediate visual order. It can turn mismatched books into a deliberate composition, connect the shelves to the room, and make a collection feel calmer or more playful.
That pleasure is not frivolous. You live with the shelves even when you are not retrieving a book from them.
Why it works visually
Color is visible from across the room. Repeated hues create blocks and transitions that the eye can follow without reading each spine. Unlike author or subject, color also asks very little explanation from a visitor.
The retrieval problem
The weakness appears when you remember the author but not the spine. Books by one writer can be scattered across several colors, a series can be separated, and a new edition can sit nowhere near an older one.
When organizing by color is fine
It works well for a collection you browse visually, books you rarely need to retrieve by author or subject, a small enough group to scan easily, or a room where the shelves' appearance is a major purpose.
It is less convincing for reference books, specialist subjects, or shared shelves where several people need a predictable return rule.
Mixed systems usually work better
You do not have to choose between a rainbow and a filing cabinet. Keep fiction alphabetical, group reference books by subject, and arrange a display shelf or a less-used collection by color. You can also use color within a broad category.
This is one example of the mixed approach described in the broader home-library organizing guide.
Let the catalog compensate
A catalog can preserve relationships the shelf does not show. Author, series, subject, and tags remain searchable while the physical location tells you which color section and shelf to inspect.
If the color arrangement spans several cases, record a simple location using the room → case → shelf method. The catalog can do the finding while the shelf does the looking good.
My practical recommendation
Try color organization on one contained section before rearranging the whole library. Live with it long enough to retrieve and return several books. If you keep finding what you want, the system is doing its job.