Example of my colour map usage

_colours.fn.scss

@function colour($name){
  @return map-get($colours, $name);
}

@function colour-darken($name, $percentage){
  @return darken( map-get($colours, $name), $percentage );
}

@function colour-lighten($name, $percentage){
  @return lighten( map-get($colours, $name), $percentage );
}

@function colour-adjust-hue($name, $percentage){
  @return adjust-hue( map-get($colours, $name), $percentage );
}

@function colour-tint($name, $percentage){
  @return tint( map-get($colours, $name), $percentage );
}

@function colour-shade($name, $percentage){
  @return shade( map-get($colours, $name), $percentage );
}

@function colour-rgba($name, $value){
  @return rgba( map-get($colours, $name), $value );
}

// http://www.google.com/design/spec/style/color.html#

@function colour-100($name){
  @return colour-lighten($name, 20);
}

@function colour-200($name){
  @return colour-lighten($name, 15);
}

@function colour-300($name){
  @return colour-lighten($name, 10);
}

@function colour-400($name){
  @return colour-lighten($name, 5);
}

@function colour-primary($name){
  @return colour($name);
}

@function colour-600($name){
  @return colour-darken($name, 5);
}

@function colour-700($name){
  @return colour-darken($name, 10);
}

@function colour-800($name){
  @return colour-darken($name, 15);
}

@function colour-900($name){
  @return colour-darken($name, 20);
}

_colours.map.scss

$colours: (
  blue-grey: #607d8b,
  grey: #9e9e9e,
  brown: #795548,
  deep-orange: #ff5722,
  orange: #ff9800,
  amber: #ffc107,
  yellow: #ffeb3b,
  lime: #cddc39,
  light-green: #8bc34a,
  green: #259b24,
  teal: #009688,
  cyan: #00bcd4,
  light-blue: #03a9f4,
  blue: #5677fc,
  indigo: #3f51b5,
  deep-purple: #673ab7,
  purple: #9c27b0,
  pink: #e91e63,
  red: #e51c23
);

style.scss

body {
  color: colour(blue-grey);
  background-color: colour-100(blue-grey);
}