Scala-ide uses colour instead of color for their property names.

Let's support both until one of the two changes. 

@soc created a [pull request](https://github.com/scala-ide/scala-ide/pull/476) for the @scala-ide team to rename their option keys to "color" instead of "colour" but it was closed until he does a little more work on it. 

In the meantime, eclipse-color-theme will not work with scala as it is looking for keys that don't exist in the scala-ide.

This pull request supports both sets of key names so scala devs can benefit from eclipse-color-themes.