ia.css: Goodie stamp should be #ffd700 (gold-colored).

Before:
![screen shot 2014-12-16 at 10 58 28 am](https://cloud.githubusercontent.com/assets/81969/5456797/0e5cd5fe-8514-11e4-9d52-1db5d5278d26.png)

After:
![screen shot 2014-12-16 at 11 09 34 am](https://cloud.githubusercontent.com/assets/81969/5456796/0e59ba04-8514-11e4-8583-c4d6949c8da7.png)