Convert normal state of clear search trigger to grayscale

Before:

![screen shot 2014-11-11 at 2 55 39 pm](https://cloud.githubusercontent.com/assets/186715/5002224/1df92912-69b3-11e4-99e5-39002af6d11b.png)

After:

![screen shot 2014-11-11 at 2 56 20 pm](https://cloud.githubusercontent.com/assets/186715/5002225/2100601c-69b3-11e4-9060-92cda5edab34.png)