Dear Hans (and other TikZ gurus), Here's a small example that fails to compile: \setupcolors [rgb=no,cmyk=yes] \usemodule [tikz] \starttext \tikz\shade[shading=ball,ball color=yellow] (0,0) circle (1cm); \stoptext Do you have any idea how to fix this? tex error > error on line 570 in file /path/to/tex/generic/pgf/frontendlayer/tikz/tikz.code.tex: ! Illegal unit of measure (pt inserted) <to be read again> , <argument> 0.000, 0.100 \pgfutil@emu@@unpack ...pt\pgf@xb =#2pt\pgf@xc =#3 pt \pgfutil@emu@mix ... \string \color@ #1\endcsname \pgf@ya =\pgf@xa \pgf@yb =... \pgfutil@colorlet ...ix \pgf@marshal !white!\@nil \xdef \pgf@marshal {\noexp... l.570 ...l@colorlet{tikz@axis@middle}{gray!50!white} 560 \def\tikz@shade@angle{0} 561 562 \pgfdeclareverticalshading[tikz@axis@top,tikz@axis@middle,tikz@axis@bottom]{axis}{100bp}{% 563 color(0bp)=(tikz@axis@bottom); 564 color(25bp)=(tikz@axis@bottom); 565 color(50bp)=(tikz@axis@middle); 566 color(75bp)=(tikz@axis@top); 567 color(100bp)=(tikz@axis@top)} 568 569 \pgfutil@colorlet{tikz@axis@top}{gray} 570 >> \pgfutil@colorlet{tikz@axis@middle}{gray!50!white} 571 \pgfutil@colorlet{tikz@axis@bottom}{white} 572 573 \pgfdeclareradialshading[tikz@ball]{ball}{\pgfqpoint{-10bp}{10bp}}{% 574 color(0bp)=(tikz@ball!15!white); 575 color(9bp)=(tikz@ball!75!white); 576 color(18bp)=(tikz@ball!70!black); 577 color(25bp)=(tikz@ball!50!black); 578 color(50bp)=(black)} 579 580 \pgfutil@colorlet{tikz@ball}{blue} ? Mojca