subtle = ({ color, theme: { colors } }) => {
  const darkBg = colors[color] && colors[color][200]
  return {
    light: {
      bg: `${color}.100`
    },
    dark: { bg: colorEmphasis(darkBg, 'lowest') }
  }
}
@description Create subtle alert styles
@param {Object} props
@property {String} color