Add more cell colors to formatting

[me-nkr]

I thought the cell color options was limited so added more cell color options 😃

Also I felt like the colorCell"Color" functions can be concluded into a single function, so concluded all of those into a new single colorCell function and removed no-more-useful code.

And lastly increased maxKeyBindLength to accommodate new cell color key bindings.

Hoping to see this come as a official chrome extension or a sheets add-on if that's possible

-- Cheers