@function powerNumber($number, $exp)

$value: 1
@if $exp > 0
  @for $i from 1 through $exp
    $value: $value * $number
@else if $exp < 0
  @for $i from 1 through -$exp
    $value: $value / $number
@return $value

@function colorLuminance($color)

$color-rgb: ('red': red($color),'green': green($color),'blue': blue($color))
@each $name, $value in $color-rgb
  $adjusted: 0
  $value: $value / 255
  @if $value < 0.03928
    $value: $value / 12.92
  @else
    $value: ($value + .055) / 1.055
    $value: powerNumber($value, 2)
  $color-rgb: map-merge($color-rgb, ($name: $value))
@return (map-get($color-rgb, 'red') * .2126) + (map-get($color-rgb, 'green') * .7152) + (map-get($color-rgb, 'blue') * .0722)

@function findColorInvert($color)

@if (colorLuminance($color) > 0.55)
  @return rgba(#000, 0.7)
@else
  @return #fff