@tokens-studio/sd-transforms/dist/color-modifiers/darken.js

Custom transforms for Style-Dictionary, to work with Design Tokens that are exported from Tokens Studio

export function darken(color, colorSpace, amount) {
    switch (colorSpace) {
        case 'lch': {
            const lightness = color.lch.l;
            const difference = lightness;
            const newChroma = Math.max(0, color.lch.c - amount * color.lch.c);
            const newLightness = Math.max(0, lightness - difference * amount);
            color.set('lch.l', newLightness);
            color.set('lch.c', newChroma);
            return color;
        }
        case 'hsl': {
            const lightness = color.hsl.l;
            const difference = lightness;
            const newLightness = Math.max(0, lightness - difference * amount);
            color.set('hsl.l', newLightness);
            return color;
        }
        case 'p3': {
            const colorInP3 = color.to('p3');
            const newRed = Math.max(0, colorInP3.p3.r - amount * colorInP3.p3.r);
            const newGreen = Math.max(0, colorInP3.p3.g - amount * colorInP3.p3.g);
            const newBlue = Math.max(0, colorInP3.p3.b - amount * colorInP3.p3.b);
            colorInP3.set('p3.r', newRed);
            colorInP3.set('p3.g', newGreen);
            colorInP3.set('p3.b', newBlue);
            return colorInP3;
        }
        case 'srgb': {
            const newRed = Math.max(0, color.srgb.r - amount * color.srgb.r);
            const newGreen = Math.max(0, color.srgb.g - amount * color.srgb.g);
            const newBlue = Math.max(0, color.srgb.b - amount * color.srgb.b);
            color.set('srgb.r', newRed);
            color.set('srgb.g', newGreen);
            color.set('srgb.b', newBlue);
            return color;
        }
        default: {
            return color.darken(amount);
        }
    }
}