Programmatically darken a Hex colour [closed]

Answer 1

A function implemented in javascript:

// credits: richard maloney 2006
function getTintedColor(color, v) {
    if (color.length >6) { color= color.substring(1,color.length)}
    var rgb = parseInt(color, 16); 
    var r = Math.abs(((rgb >> 16) & 0xFF)+v); if (r>255) r=r-(r-255);
    var g = Math.abs(((rgb >> 8) & 0xFF)+v); if (g>255) g=g-(g-255);
    var b = Math.abs((rgb & 0xFF)+v); if (b>255) b=b-(b-255);
    r = Number(r < 0 || isNaN(r)) ? 0 : ((r > 255) ? 255 : r).toString(16); 
    if (r.length == 1) r = '0' + r;
    g = Number(g < 0 || isNaN(g)) ? 0 : ((g > 255) ? 255 : g).toString(16); 
    if (g.length == 1) g = '0' + g;
    b = Number(b < 0 || isNaN(b)) ? 0 : ((b > 255) ? 255 : b).toString(16); 
    if (b.length == 1) b = '0' + b;
    return "#" + r + g + b;
} 

Example:

> getTintedColor("ABCEDEF", 10)
> #c6f7f9

Answer 2

Well, I don't have any pseudocode for you, but a tip. If you want to darken a color and maintain its hue, you should convert that hex to HSB (hue, saturation, brightness) rather than RGB. This way, you can adjust the brightness and it will still look like the same color without hue shifting. You can then convert that HSB back to hex.

Answer 3

You should consider darken the color in L*a*b* color space. Here's an example in JavaScript using chroma.js:

chroma.hex("#FCFC00").darker(10).hex()  // "#dde000"

Answer 4

• Split the hex color into its RGB components.
• Convert each of these components into an integer value.
• Multiply that integer by a fraction, such as 0.5, making sure the result is also integer.
  • Alternatively, subtract a set amount from that integer, being sure not to go below 0.
• Convert the result back to hex.
• Concatenate these values in RGB order, and use.