Workflow
Extract a color palette from a screenshot on Mac
Designers and editors collect color the same way they collect footage — by screenshotting things they like. Color Index turns those screenshots into usable palettes: the dominant hex codes, shown as swatches and saved as a clean .txt.
How the workflow works
Switch to Extract → Color Index
In Cromoteca's Format section, choose Extract, then Color Index. The input area becomes an image drop zone.
Drop in a screenshot or image
Drag a screenshot onto the area or click Choose Image. Color Index supports PNG, JPG, JPEG, and WEBP.
Read the palette
Cromoteca analyzes the image locally and shows the dominant colors as swatches with their hex codes, sorted by how much of the image they cover.
Copy or save
Copy a single hex with a click, copy the whole set, or run Start Extract to save a Color-Index-name.txt palette to your destination folder.
Reuse it anywhere
Paste the hex codes straight into your design tool, brief, or style sheet — the .txt lives in your archive next to the references it came from.
FAQ
Does Color Index analyze images locally?
Yes. Color extraction runs on your Mac — the image is not uploaded anywhere. The palette is shown in the app and written to a .txt in your destination folder.
How many colors does it extract?
A practical set — typically up to about ten dominant colors, with near-identical shades merged and tiny noise dropped, so you get a usable palette rather than hundreds of swatches.
Which image formats are supported?
PNG, JPG, JPEG, and WEBP are the common ones, plus other formats macOS can read. Screenshots (which are usually opaque) work especially well.
Are the colors labeled by role like background or text?
Colors are sorted by dominance and tagged with a light hint (light, dark, accent, or mid) from their luminance and saturation. These are honest hints, not layout-aware role detection.