thank you Harban and Keith McKay.

\startMPpage
>       picture tt ; tt := lmt_outline [
>           kind = "path",
>           text = "\definedfont[name:texgyrepagellabold*default]foo f o o",
>       ] ;
>
>       fill
>          for i within tt : pathpart i && endfor cycle
>          withshademethod "linear"
>          withshadedirection down
>          withshadecolors (red, blue) ;
> \stopMPpage
>
> I'll add this:
>
> \startMPpage
>      draw lmt_outline [
>          kind = "outline",
>          text = "\definedfont[name:texgyrepagellabold*default]foo f o o",
>      ]
>          withshademethod "linear"
>          withshadedirection down
>          withshadecolors (red, blue)
>      ;
> \stopMPpage
>
> so a single path option (no picture)
>
> Hans
>

Thank you so much for the sample examples
it would be great to also make text select able in output pdf
the third example currently does not work. did you mean you will add this
feature for next updates?