rebeccapurple был выбран голосованием. This color has meaningful history to CSS, is a keyword easily used in css rebeccapurple and has great contrast with the bright light letters on it.
https://meyerweb.com/eric/thoughts/2014/06/19/rebeccapurple/
> Following a proposal sent to social media, it is suggested
> to add the named color 'rebeccapurple', for value #663399, to
> CSS Color Level 4. This is a tribute to Eric Meyer's daughter
> who recently passed away and a mark of support from all the
> Web community to Eric. I requested to ping Eric to be absolutely
> sure he is ok with this; he responded "he was honored by the gesture,
> and would love to accept it".
😢