message: Adds gray to color styles
diff: .Color
  - color-states = channel-public channel-closed channel-private state-premium
  + kolors = channel-public channel-closed channel-private state-premium gray-light
  - for state in color-states
  - &--{state}
  + for kolor in kolors
  + &--{kolor}
  &, input
  - color lookup('colors-' + state)
  + color lookup('colors-' + kolor)
  border-color rgba(@color, 0.3)
  