Colour command showing side effect upon subsequent text

Question

I introduced colour to a QED command, but the colour has side effect on the text that follows it. I want the colour to be restricted to the symbol only.

\documentclass[a4paper,12pt]{article}
\usepackage{xcolor}
\ExplSyntaxOn
\definecolor{dblue}{RGB}{0,0,139}
\colorlet{celestk}{dblue}
\NewDocumentCommand{\wvQed}{O{celestk}o}
  {
    \IfNoValueTF{#2}{\color{#1}}{\color[#1]{#2}}
    \hfill\nabla
  }
\ExplSyntaxOff
\begin{document}
Tantra is an Expansion Device. \wvQed
The word appears in the hymns of the Rigveda such as in 10.71
\end{document}

You are also missing $. As requested before, please make sure your code compiles and please link and attribute when you use code provided by others. Strictly speaking, this is a legal requirement of SE's licence. (Though I don't know how much would be considered subject to copyright.) — cfr, Oct 16 '23 at 00:09
You have already been shown how to use a group or \textcolor to scope color, you would find it easier to find existing answers if you did not delete your account aftereach question — David Carlisle, Oct 16 '23 at 09:43

score 1 · Accepted Answer · answered Oct 16 '23 at 00:13

expl3 syntax isn't doing much for you here except saving the need to comment line endings. While that's convenient, I wouldn't change category codes for it.

You need $ to compile this. You need a group to limit the effect of the colour change.

\documentclass[a4paper,12pt]{article}
\usepackage{xcolor}
\definecolor{dblue}{RGB}{0,0,139}
\colorlet{celestk}{dblue}
\NewDocumentCommand{\wvQed}{O{celestk}o}
  {%
    \begingroup
      \IfNoValueTF{#2}{\color{#1}}{\color[#1]{#2}}%
      \hfill$\nabla$%
    \endgroup
  }
\begin{document}
Tantra is an Expansion Device. \wvQed
The word appears in the hymns of the Rigveda such as in 10.71
\end{document}

Colour command showing side effect upon subsequent text

1 Answers1