@mixin color($hex, $opacity: 1, $suffix: null)
  color: rgba($hex, $opacity)$suffix

@mixin border-color($hex, $opacity: 1, $suffix: null)
  border-color: rgba($hex, $opacity)$suffix

@mixin background-color($hex, $opacity: 1, $suffix: null)
  background-color: rgba($hex, $opacity)$suffix

@mixin scrollbar-color($hex1, $hex2, $opacity1: 1, $opacity2: 1, $suffix: null)
  scrollbar-color: rgba($hex1, $opacity1) rgba($hex2, $opacity2)$suffix

@mixin stroke($hex, $opacity: 1, $suffix: null)
  stroke: rgba($hex, $opacity)$suffix