Question 1

How does the color-by-number generator work?

Accepted Answer

Upload a photo and the tool shrinks it to a grid, reduces the colors to a small palette (you choose how many), then assigns each color a number. Each cell shows its number so you know exactly which color to paint it.

Question 2

What is the best number of colors to use?

Accepted Answer

For kids and simple coloring pages, 8–12 colors works well. For detailed adult coloring pages, 16–24 colors preserves more detail. More colors means a more accurate image but a busier sheet.

Question 3

Can I generate a black-and-white outline version?

Accepted Answer

Yes. Use the Outline mode — it shows only the cell borders and numbers on a white background, ready to be colored by hand. Switch back to Filled mode to see the colored preview.

Question 4

Is my uploaded photo uploaded to a server?

Accepted Answer

No. The entire color-quantization and grid-mapping process runs locally in your browser using the Canvas API. Your photo is never sent to any server.