Le 28 avr. 2022 =C3=A0 08:41, Fabrice L = <fabrice.alpha@gmail.com> a =C3=A9crit :

Hi Keith,

Le 28 avr. 2022 =C3=A0 06:05, = Keith McKay via ntg-context <ntg-context@ntg.nl> a =C3=A9crit :

Hi,
In the MWE below I define an rgb = colour, myColor1, using random numbers for the r, g and b components. I = then use it to fill a unitsquare the size of the page, which works as = expected. In the loop that follows I then use the defined colour, = myColor1, along with white and the variable r to create shades of = myColor1 as in the MWE below. However, myColor1 is not recognised in the = loop and seems to be replaced by black, although if I use a predefined = colour, in this case BurntSienna from the crayola collection, it works = as expected. I have tried a number of ways to get this to work as = shown in the code but without success. I would be grateful for any = suggestions.
Best = Wishes
Keith = McKay
%%%%%%%%%%%%%%%%%%%%MWE%%%%%%%%%%%%%
\setuppapersize[A4,portrait]
\usecolors[crayola]
\starttext
\dorecurse{10}{
\startMPpage
StartPage;
\definecolor[name=3D"myColor1", r =3D = uniformdeviate(1), g =3D uniformdeviate(1), b =3D uniformdeviate(1) ] = ;
fill unitsquare xscaled PaperWidth yscaled = PaperHeight withcolor "myColor1";
for i =3D2= step 2 until 10:
r :=3D i/10;
fill = unitsquare xscaled 5cm yscaled .5cm shifted (1cm,i*cm) = withcolor(r[\MPcolor{BurntSienna},white]);
fill = unitsquare xscaled 5cm yscaled .5cm shifted (7cm,i*cm) = withcolor(r[\MPcolor{myColor1}, white]);
fill = unitsquare xscaled 5cm yscaled .5cm shifted (13cm,i*cm) = withcolor(r[\MPcolor{"myColor1"}, white]);
%fill = unitsquare xscaled 5cm yscaled .5cm shifted (13cm,i*cm) = withcolor(r[myColor1 , white]); This line causes an error.
endfor;
StopPage;
\stopMPpage
}

\stoptext
%%%%%%%%%%%%%%%%%%%%%%%%%%%end = MWE%%%%%%%%%%%

Here is a = solution, with works here, defining in another way the color =C2=AB = myColor =C2=BB:

\setuppapersize[A4,portrait]
\usecolors[crayola]
\starttext
\dorecurse{2}{
\startMPpage
StartPage;
color myColor ;
myColor :=3D = (uniformdeviate(1),uniformdeviate(1),uniformdeviate(1));
fill unitsquare xscaled PaperWidth yscaled PaperHeight = withcolor myColor;
for i =3D2 step 2 until = 10:
r :=3D i/10;
fill = unitsquare xscaled 5cm yscaled .5cm shifted (1cm,i*cm) = withcolor(r[\MPcolor{BurntSienna},white]);
fill = unitsquare xscaled 5cm yscaled .5cm shifted (7cm,i*cm) = withcolor(r[\MPcolor{myColor1}, white]);
fill = unitsquare xscaled 5cm yscaled .5cm shifted (13cm,i*cm) = withcolor(r[\MPcolor{"myColor1"}, white]);
%fill = unitsquare xscaled 5cm yscaled .5cm shifted (13cm,i*cm) = withcolor(r[myColor1 , white]); This line causes an = error.
endfor;
StopPage;
\stopMPpage
}

\stoptext

I forgot to remove =C2=AB myColor1 =C2=BB = from the others parts of the = code.

\setuppapersize[A4,portrait]

\usecolors[cr= ayola]

\starttext

\dorecurse{10}{

\startMPpa= ge

StartPage;

color myColor ;

myColor :=3D = (uniformdeviate(1),uniformdeviate(1),uniformdeviate(1));

fill = unitsquare xscaled PaperWidth yscaled PaperHeight withcolor = myColor;

for i =3D2 step 2 until 10:

r :=3D = i/10;

fill unitsquare xscaled 5cm yscaled .5cm shifted = (1cm,i*cm) withcolor(r[\MPcolor{BurntSienna},white]);

fill = unitsquare xscaled 5cm yscaled .5cm shifted (7cm,i*cm) = withcolor(r[myColor, white]);

fill unitsquare xscaled 5cm = yscaled .5cm shifted (13cm,i*cm) withcolor(r[myColor, = white]);

%fill unitsquare xscaled 5cm yscaled .5cm shifted = (13cm,i*cm) withcolor(r[myColor1 , white]); This line causes an = error.

endfor;

StopPage;

\stopMPpage

}