How color inversion works
Inverting subtracts each color channel from 255. Black (0, 0, 0) becomes white (255, 255, 255), and rgb(37, 99, 235), a mid blue, becomes rgb(218, 156, 20), a deep yellow. Every color moves to the opposite side of the color wheel and light areas swap with dark ones, so a sunny sky turns orange-brown and shadows turn bright. Transparency is not inverted, so the transparent parts of a PNG stay transparent. Because the operation is purely arithmetic, it is predictable: the same image always inverts to the same result.
Partial inversion with the slider
The tool opens at 100%, a full negative. Lower values blend the inverted image with the original. Something curious happens at 50%: every pixel lands on the same mid grey, because each value is averaged with its own opposite. Settings between 0 and 50% give a washed-out, low-contrast version of the original, and settings between 50 and 100% give a faded negative. Values close to 100% keep most of the contrast while softening the blacks slightly, which can make an inverted diagram easier on the eyes.
Uses and saving the result
Inversion is used to view scanned black and white negatives as positives, to make dark versions of diagrams, line art and scanned documents, to create graphic poster effects, and to spot details that are hard to see in very bright or very dark areas.
The color inverter runs in the full editor, so you can also crop, rotate, adjust brightness or contrast, or add text before saving, and everything is applied in one export. The preview is drawn in your browser, while the final file is processed on the server at full resolution. PNG files stay PNG with their transparency, and other formats are saved as high-quality JPEG.