Grayscale Color Converter

Weighted gray versus desaturation

Setting a color's HSL saturation to zero keeps its HSL lightness, which turns pure yellow #FFFF00 and pure blue #0000FF into the same #808080. The weighted formula here follows how bright each channel looks instead: yellow becomes #EDEDED and blue #121212. The weights are applied to the stored sRGB values, a fast approximation, so the gray is close to, but not always exactly, the brightness the contrast checker calculates for the original color.

Testing a palette's brightness

Converting each color in a palette to gray shows whether the colors differ in brightness or only in hue. Two chart series or status colors that land on nearly the same gray will be hard to tell apart for many color-blind readers and on a black-and-white printout. Make one of them lighter or darker until the grays are clearly different, rather than relying on hue alone.

How to use it

1. Enter valid #RGB or #RRGGBB values and any requested percentage.
2. Run the fixed browser-local color operation.
3. Review the swatches and copy the result or palette values.

Privacy & limitations

Color values stay on this device. Contrast output is a mathematical checker, not a blanket WCAG compliance guarantee; context, font rendering, non-text contrast, and user interface states still need review.