Color Wheel
Upload an image to extract perimeter colors from its hue/saturation gamut.
Add at least 3 primaries to export a hue × value PNG atlas.
CMYK Gamut Builder
Click on the color wheel to add primary colors. Drag a point to move it. Right-click a point to remove it. Select a primary in the sidebar to adjust its value, or upload a photo to auto-generate perimeter colors.