9.29.1 Top new questions this week

9.29.1.1 xcolor: How to get the complementary color
9.29.1.2 Display system in systeme
9.29.1.3 Text not respecting \text within NewDocumentCommand within align*
9.29.1.4 Newer versions of LaTeX fail to ignore spaces after display math environments which end with two dollar signs ($$) and contain \eqno
9.29.1.5 Can I general this code to draw a regular polyhedron?
9.29.1.6 font color does not work in front of S column of `siunitx`
9.29.1.7 Macro for printing monomials
9.29.1.1 xcolor: How to get the complementary color

https://tex.stackexchange.com/landing/r/digest?cta=question&id=684480

Is there a LaTex-style way to get the complementary color? 
For example, a corresponding command in the xcolor package? 
\documentclass[]{book} 
\usepackage{xcolor} 
\definecolor{Acolor}{named}{red} 
\... 
[color]
 
asked by cis https://tex.stackexchange.com/landing/r/digest?cta=user&id=46023 Score of 10
answered by Rmano https://tex.stackexchange.com/landing/r/digest?cta=user&id=38080 Score of 16
9.29.1.2 Display system in systeme

https://tex.stackexchange.com/landing/r/digest?cta=question&id=684494

I'm new to the systeme package. I was reading the manual to get to know it, but unfortunately it is written in French. I want to typeset the following 
The best I can come up with is the following ... 
[systeme]
 
asked by Tolaso https://tex.stackexchange.com/landing/r/digest?cta=user&id=71437 Score of 8
answered by Mico https://tex.stackexchange.com/landing/r/digest?cta=user&id=5001 Score of 6
9.29.1.3 Text not respecting \text within NewDocumentCommand within align*

https://tex.stackexchange.com/landing/r/digest?cta=question&id=684710

Within an align* environment I have lines of the form 
\Rightarrow &<\texttt{Program Code}, [a \mapsto 1, b \mapsto 2]> &\text{Rule Name}\\ 
\Rightarrow &<\texttt{Program Code 2}, [... 
[align] [xparse]
 
asked by Harith https://tex.stackexchange.com/landing/r/digest?cta=user&id=233118 Score of 7
answered by Clara https://tex.stackexchange.com/landing/r/digest?cta=user&id=238422 Score of 7
9.29.1.4 Newer versions of LaTeX fail to ignore spaces after display math environments which end with two dollar signs ($$) and contain \eqno

https://tex.stackexchange.com/landing/r/digest?cta=question&id=684207

The LaTeX file 
\documentclass[12pt]{article} 
\begin{document} 
$$ a \eqno 1 $$ 
N\\N 
$$ a \eqno 1 $$% 
N\\N 
\end{document} 
produces an unwanted space after the first displayed equation under "... 
[math-mode]
 
asked by Gabriel A. Lozada https://tex.stackexchange.com/landing/r/digest?cta=user&id=295947 Score of 7
answered by David Carlisle https://tex.stackexchange.com/landing/r/digest?cta=user&id=1090 Score of 10
9.29.1.5 Can I general this code to draw a regular polyhedron?

https://tex.stackexchange.com/landing/r/digest?cta=question&id=684305

In this code, I draw a regular polyhedron whose base is an equilateral triangle. 
\documentclass[tikz,border=3mm]{standalone} 
\usepackage{tikz-3dplot} 
\begin{document} 
\tdplotsetmaincoords{70}{... 
[tikz-3dplot]
 
asked by John Paul Peter https://tex.stackexchange.com/landing/r/digest?cta=user&id=250010 Score of 6
answered by Juan CastaA~+-o https://tex.stackexchange.com/landing/r/digest?cta=user&id=231368 Score of 12
9.29.1.6 font color does not work in front of S column of `siunitx`

https://tex.stackexchange.com/landing/r/digest?cta=question&id=684208

Given is a table with factors from x1 to x1000000000 then x0.1 and x0.01 in the fourth column. 
The S column of siunitx takes care of the alignment. 
Unexpectedly, however, the font color no longer ... 
[tabularx] [siunitx]
 
asked by Michael.H https://tex.stackexchange.com/landing/r/digest?cta=user&id=233250 Score of 5
answered by Jasper Habicht https://tex.stackexchange.com/landing/r/digest?cta=user&id=47927 Score of 4
9.29.1.7 Macro for printing monomials

https://tex.stackexchange.com/landing/r/digest?cta=question&id=684466

This is a follow-up to my previous question How to convert a sequence of integers into a monomial 
Question 1. Is it possible a macro that takes two inputs 
varname:   { x1, x2, ... , xn } 
exp:       { ... 
[latex3]
 
asked by underflow https://tex.stackexchange.com/landing/r/digest?cta=user&id=183182 Score of 5
answered by egreg https://tex.stackexchange.com/landing/r/digest?cta=user&id=4427 Score of 3