_colors.scss

$_gmd-colors: (
  red: (
    50: #fde0dc,
    100: #f9bdbb,
    200: #f69988,
    300: #f36c60,
    400: #e84e40,
    500: #e51c23,
    600: #dd191d,
    700: #d01716,
    800: #c41411,
    900: #b0120a,
    A100: #ff7997,
    A200: #ff5177,
    A400: #ff2d6f,
    A700: #e00032
  ),
  pink: (
    50: #fce4ec,
    100: #f8bbd0,
    200: #f48fb1,
    300: #f06292,
    400: #ec407a,
    500: #e91e63,
    600: #d81b60,
    700: #c2185b,
    800: #ad1457,
    900: #880e4f,
    A100: #ff80ab,
    A200: #ff4081,
    A400: #f50057,
    A700: #c51162
  ),
  purple: (
    50: #f3e5f5,
    100: #e1bee7,
    200: #ce93d8,
    300: #ba68c8,
    400: #ab47bc,
    500: #9c27b0,
    600: #8e24aa,
    700: #7b1fa2,
    800: #6a1b9a,
    900: #4a148c,
    A100: #ea80fc,
    A200: #e040fb,
    A400: #d500f9,
    A700: #aa00ff
  ),
  deep-purple: (
    50: #ede7f6,
    100: #d1c4e9,
    200: #b39ddb,
    300: #9575cd,
    400: #7e57c2,
    500: #673ab7,
    600: #5e35b1,
    700: #512da8,
    800: #4527a0,
    900: #311b92,
    A100: #b388ff,
    A200: #7c4dff,
    A400: #651fff,
    A700: #6200ea
  ),
  indigo: (
    50: #e8eaf6,
    100: #c5cae9,
    200: #9fa8da,
    300: #7986cb,
    400: #5c6bc0,
    500: #3f51b5,
    600: #3949ab,
    700: #303f9f,
    800: #283593,
    900: #1a237e,
    A100: #8c9eff,
    A200: #536dfe,
    A400: #3d5afe,
    A700: #304ffe
  ),
  blue: (
    50: #e7e9fd,
    100: #d0d9ff,
    200: #afbfff,
    300: #91a7ff,
    400: #738ffe,
    500: #5677fc,
    600: #4e6cef,
    700: #455ede,
    800: #3b50ce,
    900: #2a36b1,
    A100: #a6baff,
    A200: #6889ff,
    A400: #4d73ff,
    A700: #4d69ff
  ),
  light-blue: (
    50: #e1f5fe,
    100: #b3e5fc,
    200: #81d4fa,
    300: #4fc3f7,
    400: #29b6f6,
    500: #03a9f4,
    600: #039be5,
    700: #0288d1,
    800: #0277bd,
    900: #01579b,
    A100: #80d8ff,
    A200: #40c4ff,
    A400: #00b0ff,
    A700: #0091ea
  ),
  cyan: (
    50: #e0f7fa,
    100: #b2ebf2,
    200: #80deea,
    300: #4dd0e1,
    400: #26c6da,
    500: #00bcd4,
    600: #00acc1,
    700: #0097a7,
    800: #00838f,
    900: #006064,
    A100: #84ffff,
    A200: #18ffff,
    A400: #00e5ff,
    A700: #00b8d4
  ),
  teal: (
    50: #e0f2f1,
    100: #b2dfdb,
    200: #80cbc4,
    300: #4db6ac,
    400: #26a69a,
    500: #009688,
    600: #00897b,
    700: #00796b,
    800: #00695c,
    900: #004d40,
    A100: #a7ffeb,
    A200: #64ffda,
    A400: #1de9b6,
    A700: #00bfa5
  ),
  green: (
    50: #d0f8ce,
    100: #a3e9a4,
    200: #72d572,
    300: #42bd41,
    400: #2baf2b,
    500: #259b24,
    600: #0a8f08,
    700: #0a7e07,
    800: #056f00,
    900: #0d5302,
    A100: #a2f78d,
    A200: #5af158,
    A400: #14e715,
    A700: #12c700
  ),
  light-green: (
    50: #f1f8e9,
    100: #dcedc8,
    200: #c5e1a5,
    300: #aed581,
    400: #9ccc65,
    500: #8bc34a,
    600: #7cb342,
    700: #689f38,
    800: #558b2f,
    900: #33691e,
    A100: #ccff90,
    A200: #b2ff59,
    A400: #76ff03,
    A700: #64dd17
  ),
  lime: (
    50: #f9fbe7,
    100: #f0f4c3,
    200: #e6ee9c,
    300: #dce775,
    400: #d4e157,
    500: #cddc39,
    600: #c0ca33,
    700: #afb42b,
    800: #9e9d24,
    900: #827717,
    A100: #f4ff81,
    A200: #eeff41,
    A400: #c6ff00,
    A700: #aeea00
  ),
  yellow: (
    50: #fffde7,
    100: #fff9c4,
    200: #fff59d,
    300: #fff176,
    400: #ffee58,
    500: #ffeb3b,
    600: #fdd835,
    700: #fbc02d,
    800: #f9a825,
    900: #f57f17,
    A100: #ffff8d,
    A200: #ffff00,
    A400: #ffea00,
    A700: #ffd600
  ),
  amber: (
    50: #fff8e1,
    100: #ffecb3,
    200: #ffe082,
    300: #ffd54f,
    400: #ffca28,
    500: #ffc107,
    600: #ffb300,
    700: #ffa000,
    800: #ff8f00,
    900: #ff6f00,
    A100: #ffe57f,
    A200: #ffd740,
    A400: #ffc400,
    A700: #ffab00
  ),
  orange: (
    50: #fff3e0,
    100: #ffe0b2,
    200: #ffcc80,
    300: #ffb74d,
    400: #ffa726,
    500: #ff9800,
    600: #fb8c00,
    700: #f57c00,
    800: #ef6c00,
    900: #e65100,
    A100: #ffd180,
    A200: #ffab40,
    A400: #ff9100,
    A700: #ff6d00
  ),
  deep-orange: (
    50: #fbe9e7,
    100: #ffccbc,
    200: #ffab91,
    300: #ff8a65,
    400: #ff7043,
    500: #ff5722,
    600: #f4511e,
    700: #e64a19,
    800: #d84315,
    900: #bf360c,
    A100: #ff9e80,
    A200: #ff6e40,
    A400: #ff3d00,
    A700: #dd2c00
  ),
  brown: (
    50: #efebe9,
    100: #d7ccc8,
    200: #bcaaa4,
    300: #a1887f,
    400: #8d6e63,
    500: #795548,
    600: #6d4c41,
    700: #5d4037,
    800: #4e342e,
    900: #3e2723
    // no accents for brown colors
  ),
  grey: (
    50: #fafafa,
    100: #f5f5f5,
    200: #eeeeee,
    300: #e0e0e0,
    400: #bdbdbd,
    500: #9e9e9e,
    600: #757575,
    700: #616161,
    800: #424242,
    900: #212121,
    1000: #000000,
    0: #ffffff // originally called 1000
  ),
  blue-grey: (
    50: #eceff1,
    100: #cfd8dc,
    200: #b0bec5,
    300: #90a4ae,
    400: #78909c,
    500: #607d8b,
    600: #546e7a,
    700: #455a64,
    800: #37474f,
    900: #263238
    // no accent for blue-grey
  )
);

@function gmd-color($color, $value: 500) {
  @if map-has-key($_gmd-colors, $color) {
    $color: map-get($_gmd-colors, $color);
    @if map-has-key($color, $value) {
      @return map-get($color, $value);
    }
    @warn "invalid value, using 500 as default";
    @return map-get($color, 500);
  }
  @warn "invalid color, using #ff0000 as default";
  @return #ff0000;
}

// Default palette
$gmd-primary: gmd-color(indigo, 500);
$gmd-primary-dark: gmd-color(indigo, 700);
$gmd-primary-light: gmd-color(indigo, 100);
$gmd-accent: gmd-color(pink, A200);
$gmd-accent-dark: gmd-color(pink, A400);
$gmd-accent-light: gmd-color(pink, A100);

@mixin gmd-palette($primary: red, $accent: pink) {
  // Generate a color palette based on $primary and $accent colors
  @if map-has-key($_gmd-colors, $primary) and map-has-key($_gmd-colors, $accent) {
    $gmd-primary: gmd-color($primary, 500);
    $gmd-primary-dark: gmd-color($primary, 700);
    $gmd-primary-light: gmd-color($primary, 100);
    $gmd-accent: gmd-color($accent, A200);
    $gmd-accent-dark: gmd-color($accent, A400);
    $gmd-accent-light: gmd-color($accent, A100);
  }
  @warn "invalid colors using defaults";
}

$_gmd-alphas: (
  dividers: .12,
  hint-text: .26,
  secondary-text: .54,
  icons: .54,
  text: .87
);

@function gmd-alpha($type) {
  @if map-has-key($_gmd-alphas, $type) {
    @return map-get($_gmd-alphas, $type);
  }
  @warn "invalid alpha type, using default 100%";
  @return 1;
}

@function gmd-alpha-color($color, $type) {
    @if map-has-key($_gmd-alphas, $type) {
      @return rgba($color, map-get($_gmd-alphas, $type));
    }
    @warn "invalid alpha type, using default 100%";
    @return rgba($color, 1);
}

// Default alpha palette based on black
$gmd-dividers: gmd-alpha-color(black, dividers);
$gmd-hint-text: gmd-alpha-color(black, hint-text);
$gmd-secondary-text: gmd-alpha-color(black, secondary-text);
$gmd-icons: gmd-alpha-color(black, icons);
$gmd-text: gmd-alpha-color(black, text);

@mixin gmd-alpha-palette($color) {
  // Generate an alpha palette based on $color
  $gmd-dividers: gmd-alpha-color($color, dividers);
  $gmd-hint-text: gmd-alpha-color($color, hint-text);
  $gmd-secondary-text: gmd-alpha-color($color, secondary-text);
  $gmd-icons: gmd-alpha-color($color, icons);
  $gmd-text: gmd-alpha-color($color, text);
}

// TEST

@include gmd-palette(blue, lime);
@include gmd-alpha-palette(gmd-color(indigo));
body {
  background-color: gmd-color(blue-grey, 300);
  color: $gmd-accent-light;
  border-color: rgba(0,0,0, gmd-alpha(dividers));
}
h1 {
  color: $gmd-text;
}
h2 {
  color: gmd-alpha-color(black, text);
  background-color: gmd-alpha-color(gmd-color(indigo, 900), dividers);
}