Make RGB Colors Lighter / Darker

example.js

/*
 * Make RGB-Colors lighter / darker
 */

var color = function(c,m,f,d){d=Math.round(f?f:0.2*256)*(m?-1:1);function k(i){return Math[m?'max':'min'](c[i]+d,m?0:255)}return[k(0),k(1),k(2)]}

/**
 * @param array RGB Colors
 * @param bool  (false)(default) Lighter / (true) Darker
 * @param floar Ratio (default: 0.2 )
 */
color( [255, 100, 100 ], false, 0.3 ); // makes rgb(255,100,100) 30 percent lighter
color( [255, 100, 100 ], true, 0.3 ); // makes rgb(255,100,100) 30 percent darker

index.js

function(c,m,f,d){d=Math.round(f?f:0.2*256)*(m?-1:1);function k(i){return Math[m?'max':'min'](c[i]+d,m?0:255)}return[k(0),k(1),k(2)]}

package.json

{
  "name": "color",
  "keywords": [ "color" ]
}

How about using sign instead of booleans to determine lighter/darker?

@140bytes see my 73bytes long fork