Color-by-Number
Generator

Works great

• Clear subject with contrast — a face, an animal, a building. The subject should stand out clearly from the background.
• Distinct color zones — areas of different color separated by clear edges (e.g. sky vs. mountains, face vs. hair).
• Well-lit, in-focus — natural or even lighting, no strong blurs.
• Colorful or tonal variety — images with several visible colors produce richer palettes.
• At least 800 × 800 px — small images may lack detail for finer grids.

Avoid

• Flat or monochromatic images — a gray wall, a plain sky, or anything where most pixels are nearly the same color. There isn't enough variation to build a meaningful palette.
• Very fine textures — close-up hair, grass, sand, or fur. These create hundreds of tiny regions that are hard to color and look cluttered.
• Very dark or overexposed photos — poor lighting hides the color differences the generator relies on.
• Busy backgrounds — a crowd, dense foliage, or a detailed cityscape behind the subject can overwhelm the main shape.