To represent colour cross-browser, devs should be able to use a Colour object

[craigfowler]

Imported from Selenium issue #54

I have noticed that various web browsers communicate information about colour in different ways. Some use ARGB, some use hex notation and so on. In order to make it easier to query for and work with colour information, there should be a class (struct?) which normalises all of these representations into one.

Such an object/model would need the following functionality:

• IEquatable<Color>
• Proprieties exposing the ARGB values
• ToHexString()
• Color Parse(string) and bool TryParse(string, out Color) static methods
• The default ToString() method should use ARGB