Hi,
As an extension of this discussion https://mail.google.com/mail/u/0/#inbox/QgrcJHsNlRfcqCPHBTrnSFbJKjGPwjbJnLL?compose=CllgCJZWxJlpNNfzrPpFwWRqsFfdXqmnxkCwWVjvXKQJBwQmBfZGvchjMbsJDKXLtKldJtpWVqq (thanks to Wolfgang), I used the MetaFun interface with lmt_text [] ; I managed to pass the text and color parameters while I did not succeed using textext (). My problem is the size of the letters which is too small.
Thank you.
Fabrice

\usecolors[xwi]

\definecolor [prune] [r=1.29,g=.20,b=.83]

\starttext

\startMPcode
 
  vardef card(expr s, c) = image(
       draw fullsquare xyscaled (2cm,4cm);
       draw fullsquare xyscaled (1.8cm,3.8cm) withcolor \MPcolor{violet};
       draw lmt_text[
       text  = s,
       color = c,
       style = "bold",
       ]
       )
  enddef;

  draw card("A",red) rotatedaround((1cm,2cm),5);  
  draw card("L",green) rotatedaround((1cm,2cm),-5) shifted(3.5cm,0);
  draw card("E",blue) rotatedaround((1cm,2cm),5) shifted(6cm,0);
  draw card("A","prune") rotatedaround((1cm,2cm),-5) shifted(9cm,0);
 
\stopMPcode

\stoptext