Support additional colors in the theme

[chrissimpkins]

@jeffpeiyt : I saw your comment on the MkDocs repository (mkdocs/mkdocs#756).

We can work on support for this if you are still interested.

[jeffpeiyt]

Thanks @chrissimpkins ! The current color in Cinder looks great and definitely not hurt to have more options.

We are trying this theme for now. More requests may be coming. Frankly my knowledge on frontend is kind of limited and just self learn on a need basis. However our team definitely has more talented frontend developers and if we decided to continue use it with more complex cases I will urge them to contribute.:-)

[chrissimpkins]

That all sounds great Jeff. I don't claim any front end expertise either. Happy to expand this as it is useful out there. Enjoy!