Color coded devices.

This patch finally set a UNIQUE color for UNIQUE device.
Because the uuid never is the same in the devices.

If not uuid, this use the path.

![captura de pantalla de 2014-02-27 11 08 41](https://f.cloud.github.com/assets/2650479/2282572/4d4dc5ce-9fb0-11e3-8cb7-28e0b40f0227.png)
![captura de pantalla de 2014-02-27 11 10 02](https://f.cloud.github.com/assets/2650479/2282582/804a8bec-9fb0-11e3-893d-6e4253491f00.png)
![captura de pantalla de 2014-02-27 11 10 08](https://f.cloud.github.com/assets/2650479/2282583/804baf90-9fb0-11e3-8f27-1d6cae8c7ec9.png)
![captura de pantalla de 2014-02-27 11 09 58](https://f.cloud.github.com/assets/2650479/2282584/80e9d508-9fb0-11e3-8019-6c6d6371b876.png)