is specifying a cell's color (in an excel spreadsheet) by its very textual content possible?

you can fill a cell with '=cos(0)' and you get displayed its value '1'.

is there some similar function(ality) to choos开发者_运维技巧e the font-color?

something like '=COLOR(the text to display, #FF0000)'.

if not, how could you achieve something like that?

here is where I come from: I write data to an excel-file (using KNIME btw) and I want to choose the font-color.

When this question was raised in the Knime forums a couple of months ago, it didn't elicit much response, so I suspect the answer is simply "No". There were plans back in 2007 for Knime to start using Apache POI to write Excel files, which should have allowed formatting, but I don't know if this ever happened... if it didn't, then Knime is probably still just writing a CSV file for Excel, which doesn't support any formatting.