Okolors generates high quality color palettes from an image for your theming needs. It does this by converting the image's pixels to the Oklab color space and then performing k-means clustering. By using a proper color space for color difference and a more accurate clustering algorithm, this helps to ensure that the generated palette is truly representative of the input image.

One of the main intended use cases for Okolors is to generate colors for a theme based off a wallpaper. In line with this goal, the Okolors also supports printing the final average colors in multiple Okhsl lightness levels. For example, you can specify a low lightness level for background colors and a high lightness for foreground text in order to achieve a certain contrast ratio. The Okhsl color space is ideal for this, because as the lightness is changed, Okhsl preserves the hue and saturation of the color (better than other color spaces like HSL).

Okolors supports jpeg, png, gif, webp, and qoi images by default. Precompiled binaries are available on Github.

If you are looking for the Okolors library, see the crates.io page or the documentation:

Let's use the following photo for the examples below.

Running Okolors for this image with the default options gives the following sRGB hex values.

> okolors 'Jewel Changi.jpg'
010202 041215 08343A DCE1E5 246673 C27E63 4A2D25 8B739B

If your terminal supports true color, then you can use -o swatch to see blocks of the output colors.

> okolors 'Jewel Changi.jpg' -o swatch

Let's get these colors in additional lightness levels using -l.

> okolors 'Jewel Changi.jpg' -l 10,30,50,70 -o swatch

If we're providing our own lightness levels, maybe we want to cluster the colors by hue and saturation only. Let's set the lightness weight to 0 using -w.

> okolors 'Jewel Changi.jpg' -w 0 -l 10,30,50,70 -o swatch

That ended up bringing out an additional pinkish color but also merged white and black into a gray. So, use this at your own discretion!

If some of the colors still seem quite similar, then you can reduce/set the number of colors through -k.

> okolors 'Jewel Changi.jpg' -k 6 -w 0 -l 10,30,50,70 -o swatch

To see all the other command line options, pass -h for a summary or --help for detailed explanations.

Here are some more examples of Okolors in action. The only CLI flag used was -s l.

Okolors is designed with performance in mind and should give fast results for even very large images. This is despite using k-means which is more accurate but slower than something like median cut quantization. Below are the palette generation times as reported by the --verbose flag. The only other flag used was -t 4 to use 4 threads.

Oftentimes, especially for large images, loading and decoding the image takes longer than it does for Okolors to generate the palette!

• kmeans-colors served as the original inspiration for Okolors. If you want to perform other k-means related operations on images or prefer the CIELAB colorspace, then check it out!
• The awesome palette library is used for all color conversions.

Okolors (binary and library) is licensed under either

• the Apache License, Version 2.0 (see LICENSE-APACHE)
• the MIT license (see LICENSE-MIT)

at your option.