dramatically enhance colors for javascript and css

Mr. Nyman and associates,

This pull request proposes subtle but important changes to the colors for JavaScript and CSS, updating them from their current colors, shown here:

![screen shot 2014-03-06 at 11 20 23 pm](https://f.cloud.github.com/assets/39759/2354715/1009a164-a5c9-11e3-8702-2420982c88a4.png)

And changing them to these:

![screen shot 2014-03-06 at 11 19 41 pm](https://f.cloud.github.com/assets/39759/2354717/1fefee80-a5c9-11e3-980c-01d357f8e992.png)

The existing colors play on the traditional and played out red and blue motifs, whereas the updated colors, purple and yellow, are not only a more 21st century color color tuple choice but also each come from existing globally proven use cases.

`#f7df1e`, the yellow used to represent JavaScript in this pull request, is also known as "JavaScript yellow" as it is the **official** yellow used in the JS logo: https://github.com/jsconf/logo.js/blob/master/js.svg#L19

`#563d7c`, aka "bootstrap purple", is an obvious choice for a CSS color refresh as this hex code represents the iconic brand of the most popular stylesheet in the universe.

In preparation for this pull request I first analyzed the current color distribution across all languages ([source available here](http://requirebin.com/?gist=9406519)):

![screen shot 2014-03-06 at 11 12 04 pm](https://f.cloud.github.com/assets/39759/2354681/d449ad50-a5c7-11e3-9c6e-550fa5d51b98.png)

As you can see, there are already a multitude of reds, yellows and purples, which assures me that these changes won't stand out relative to other colors used on GitHub today.

In closing I would like to leave you with this photo

![1efa19a864fe11e392800a3677605d12_8](https://f.cloud.github.com/assets/39759/2354756/5797eae4-a5ca-11e3-99f8-43147d02e9d3.jpg)