Thank you, Hans for your answer.

I tried your code and it works fine. But where do the color schemes default
and whatever come from? How can they be changed?

Best regards

Marcus Vinicius

On Thu, Jul 16, 2020, 04:19 Hans Hagen <j.hagen@xs4all.nl> wrote:

> On 7/16/2020 7:32 AM, Marcus Vinicius Mesquita wrote:
> > Dear list
> >
> > I need to typeset a book for kids wich contains texts where each letter
> > is assigned a fixed color, for example:
> >
> > A - - > red;
> > B - - > blue;
> > ...
> > Z - - > green.
> >
> > What would be the best way to do this? TIA.
> There's more ways to do this but here is one:
>
> (1) make a file: colorfont.lfg:
>
> return {
>      name = "coloralphabet",
>      colorschemes = {
>          default = {
>              [1] = { "a", "e" },
>              [2] = { "i", "o", "u" },
>          },
>          whatever = {
>              [1] = { "65:90" },
>              [2] = { },
>              [3] = { },
>              [4] = { "97:122" },
>          }
>      }
> }
>
> There is some more possible but this wil do ...
>
> (2) You define a font with these goodies attached:
>
> \setupbodyfont[plex,10pt]
>
> \definefontfeature
>    [MyFeaturesA] [default]
>    [goodies={colorfont},colorscheme=default,liga=no]
>
> \definefontfeature
>    [MyFeaturesB] [default]
>    [goodies={colorfont},colorscheme=whatever,liga=no]
>
> \definefont[MyFontA][Serif*MyFeaturesA]
> \definefont[MyFontB][Serif*MyFeaturesB]
>
> (3) and use it this way:
>
> \starttext
>
> \setfontcolorscheme[1] {\MyFontA \samplefile{tufte}}\par
> \setfontcolorscheme[2] {\MyFontA \samplefile{tufte}}\par
> \setfontcolorscheme[3] {\MyFontA \samplefile{tufte}}\par
>
> \page
>
> \setfontcolorscheme[1] {\MyFontB \samplefile{tufte}}\par
> \setfontcolorscheme[2] {\MyFontB \samplefile{tufte}}\par
> \setfontcolorscheme[3] {\MyFontB \samplefile{tufte}}\par
>
> \stoptext
>
> Now, this is pretty (more than a decade) old functionality from early
> days of mkiv/luatex when it was used for some tracing (by Idris) and it
> still works (surprise).
>
> Today I would definitely use more recent trickery. If there is real
> demand for this I can have a look at it, after all it's "kind of fun"
> (as is most of font stuff).
>
> Hans
>
> -----------------------------------------------------------------
>                                            Hans Hagen | PRAGMA ADE
>                Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
>         tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl
> -----------------------------------------------------------------
>