You can use the headcolor key to change the color of the footnote number.6. September 2015 13:15Indeed, this helped. Thanks.
For the record: in order to keep the position of the number in the footnote high, one has to use:\def\redfootnotenumber#1{\color[red]{\high{#1}}}\setupnotation[footnote][numbercommand=\redfootnotenumber]