The full list of transformations:
'colour' => 'color',
'grey' => 'gray',
'!please' => '!important',
'transparency' => 'opacity',
'centre' => 'center',
'plump' => 'bold',
'photograph' => 'image',
'capitalise' => 'capitalize'
In case someone actually tries to use this in production (lol), I'm wouldn't
trust the transformation to this search/replace regex: '/(?:(?:\s|\t)*|\;)([\w-]*):/i'
You know, considering CSS is context-free 'n all.