<div dir="ltr"><div>Hello Philip<br></div><div><br></div><div>I don't know if the following would be classed as simple, but it puts a grey background to the second line of the table, and if required frequently the code could be wrapped up in a control sequence:</div><div><br></div><div>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">\input pstricks<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">\tabskip 0pt<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">\halign to
\hsize{%<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">#\hfil \tabskip
0pt plus 1em&<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">#\hfil&<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">#\hfil&<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">#\hfil&<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">#\hfil\tabskip
0pt\cr<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">123& 456&
789& 101112&131415\cr<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">\newrgbcolor{jwgrey}{0.9
0.9 0.9}<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">\pspolygon[fillstyle=solid,fillcolor=jwgrey,linestyle=none]%<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">(0pt,-0.35\baselineskip)%<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">(\hsize,-0.35\baselineskip)%<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">(\hsize,0.75\baselineskip)%<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">(0pt,0.75\baselineskip)\cr<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">\noalign{\kern
-\baselineskip}<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">123& 456&
789& 101112&131415\cr<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">123& 456&
789& 101112&131415\cr<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">123& 456&
789& 101112&131415\cr<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">123& 456&
789& 101112&131415\cr<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">123& 456&
789& 101112&131415\cr}\par<span></span></span></p>
<p class="gmail-MsoPlainText" style="margin:0cm;font-size:10.5pt;font-family:Consolas"><span style="font-family:"Courier New"">\vfill \eject
\bye<span></span></span></p>
</div><div><br></div><div><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div>Best wishes<br></div><div></div><br><div>John<br></div><br></div></div></div></div></div></div></div></div></div><div id="DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2"><br>
<table style="border-top:1px solid #d3d4de">
<tr>
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</td>
</tr>
</table><a href="#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2" width="1" height="1"></a></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, 3 Mar 2021 at 11:39, Philip Taylor <<a href="mailto:P.Taylor@hellenic-institute.uk">P.Taylor@hellenic-institute.uk</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">May I ask if there is a simple way to apply a background colour to some <br>
(but not all) rows of an \halign. UNIV = plain XeTeX, not XeLaTeX.<br>
-- <br>
Philip Taylor<br>
</blockquote></div>