lib/colour.js
function tint (rgb) {
  const colour = color(rgb);
  this.options.tintA = colour.a();
  this.options.tintB = colour.b();
  return this;
}
function tint (rgb) {
  const colour = color(rgb);
  this.options.tintA = colour.a();
  this.options.tintB = colour.b();
  return this;
}
function tint ( rgb ) { const colour = color ( rgb ) ; this . options . tintA = colour . a ( ) ; this . options . tintB = colour . b ( ) ; return this ; }
Tint the image using the provided chroma while preserving the image luminance.
An alpha channel may be present and will be unchanged by the operation.

@param {String|Object} rgb - parsed by the [color](https://www.npmjs.org/package/color) module to extract chroma values.
@returns {Sharp}
@throws {Error} Invalid parameter
Tint the image using the provided chroma while preserving the image luminance . An alpha channel may be present and will be unchanged by the operation .