fix color styles in international emails

we need to practice using loomio in different languages. I happen to be using greek at the moment and caught a bug: 

 
![image](https://f.cloud.github.com/assets/2665886/2317300/844d4256-a349-11e3-8361-8723831034e4.png)

fixed:
![image](https://f.cloud.github.com/assets/2665886/2317303/8a821d68-a349-11e3-9c12-9a5a77601d0c.png)