% PDF/A-1b:2005

\enabletrackers[backend.xmp]

\setupbackend
  [format=PDF/A-1b:2005,
   intent=sRGB IEC61966-2.1, % use <info> entry here; otherwise problems with predefined default profile
   profile=sRGB.icc, % use <filename> here
 % profile={sRGB.icc,default_gray.icc}]
   level=0]

\setupcolors[cmyk=no]
\definecolor[rgbblack][b=0.01]
\definecolor[transtest][r=1,g=1,t=.25]% transparency is not allowed



\starttext

\starttextcolor[rgbblack] % forced /DeviceGray causes problems; we need a trigger

Test for PDF/A-1b:2005

\stoptextcolor

\hbox\bgroup
    \blackrule[width=1cm,height=1cm,color=red]
    \blackrule[width=1cm,height=1cm,color=green]
    \blackrule[width=1cm,height=1cm,color=blue]
    \blackrule[width=1cm,height=1cm,color=rgbblack]
    \blackrule[width=1cm,height=1cm,color=transtest]\hskip-.5cm
    \blackrule[width=1cm,height=1cm,color=transtest]
\egroup

\stoptext