Update README.md

Author: Gummibeer

README.md

@@ -8,7 +8,7 @@
 [![Code Coverage](https://img.shields.io/scrutinizer/coverage/g/Astrotomic/laravel-translatable/master.svg?style=flat-square)](https://scrutinizer-ci.com/g/Astrotomic/laravel-translatable/) 
 [![Latest Version](http://img.shields.io/packagist/v/astrotomic/laravel-translatable.svg?style=flat-square)](https://packagist.org/packages/astrotomic/laravel-translatable) 
 [![MIT License](https://img.shields.io/github/license/Astrotomic/laravel-translatable.svg?color=blue&style=flat-square)](https://github.com/Astrotomic/laravel-translatable/blob/master/LICENSE)
-[![GitBook](https://img.shields.io/badge/GitBook-Astrotomic-blueviolet.svg?style=flat-square)](https://docs.astrotomic.info/laravel-translatable)
+[![GitBook](https://img.shields.io/badge/GitBook-Astrotomic-7e57c2.svg?style=flat-square)](https://docs.astrotomic.info/laravel-translatable)
 
 ![Laravel Translatable](docs/.gitbook/assets/laravel-translatable.png)