More keyboard shortcuts for Custom Text Colours and Highlights

Please add a shortcut for colouring the text with custom colours, the shortcut for highlighting and colouring the texts already exists but it would be lovely if we could get couple more keyboard shortcuts for custom colours, as the 6 default colours are too dull and not adjustable.

Or it would be EVEN BETTER if we could get the options to replace the default text colour options to our own preferred custom colours.