Improve clarity of specularColor() example

[JetStarBlues]

The current example does not do the best job of showcasing specularColor. Since the colors of the pointlights are set to the same value as the specular color, it is not clear what the specular color adds to the scene. For example, if you comment out the lines with calls to specularColor(), the change the omission makes is not obvious.

current

current with specularColor lines commented out

The example I have replaced it with aims to make the relationship more clear. Here is a live version. The light is given a white color, while the specular color is set to red. By clicking the mouse, you can toggle whether the specular color is set to red, or not set (and thus the default of white).

change with red specular color

change with default specular color

Change as docs:

[stalgiag]

two tiny comments

[JetStarBlues]

@stalgiag bumping this PR for review. Previously updated as per requested changes.