message: Add color package to README
diff: @@ -11,6 +11,7 @@ applications that leverage a Superset backend :chart_with_upwards_trend:
  | Package | Version |
  |--|--|
  +| [@superset-ui/color](https://github.com/apache-superset/superset-ui/tree/master/packages/superset-ui-color) | [![Version](https://img.shields.io/npm/v/@superset-ui/color.svg?style=flat-square)](https://img.shields.io/npm/v/@superset-ui/color.svg?style=flat-square) |
  | [@superset-ui/connection](https://github.com/apache-superset/superset-ui/tree/master/packages/superset-ui-connection) | [![Version](https://img.shields.io/npm/v/@superset-ui/connection.svg?style=flat-square)](https://img.shields.io/npm/v/@superset-ui/connection.svg?style=flat-square) |
  | [@superset-ui/core](https://github.com/apache-superset/superset-ui/tree/master/packages/superset-ui-core) | [![Version](https://img.shields.io/npm/v/@superset-ui/core.svg?style=flat-square)](https://img.shields.io/npm/v/@superset-ui/core.svg?style=flat-square) |
  | [@superset-ui/translation](https://github.com/apache-superset/superset-ui/tree/master/packages/superset-ui-translation) | [![Version](https://img.shields.io/npm/v/@superset-ui/translation.svg?style=flat-square)](https://img.shields.io/npm/v/@superset-ui/translation.svg?style=flat-square) |
  