How to draw a solid colored circle?

Question

I am working on some book writing. For that I need to draw circle filled with red color.

I tried \circle but it generate black circle only. How can I fill it with color?

Answer 1

One easy way would be to use TikZ as in the following MWE

\documentclass[a4paper,12pt]{scrartcl}
\usepackage{tikz}

\begin{document}
Some Text \tikz\draw[red,fill=red] (0,0) circle (.5ex); further text
\end{document}

which produces

Where the first red defines the line style of the drawn circle to be red and the fill=red specifies, that its solid red. You could also use black,fill=red to obtain a red circle with a black border. Finally of course the .5ex is the radius of the circle.

Answer 2

Another solution with TikZ, but this one creates a command \tikzcircle to be used in the document:

\newcommand{\tikzcircle}[2][red,fill=red]{\tikz[baseline=-0.5ex]\draw[#1,radius=#2] (0,0) circle ;}%

It takes one mandatory argument, the radius of the circle and an optional argument that helps in customizing the circle's aspect.

The code:

\documentclass[a4paper,11pt]{article}
\usepackage{tikz}

\newcommand{\tikzcircle}[2][red,fill=red]{\tikz[baseline=-0.5ex]\draw[#1,radius=#2] (0,0) circle ;}%

\begin{document}
This is my text \tikzcircle{2pt} followed by \tikzcircle[green, fill=blue]{1.5pt} some other text \tikzcircle[fill=orange]{3pt} and some other text
\end{document}

The result:

Answer 3

\documentclass{article}
\usepackage{xcolor,pict2e}% to allow any radius
\begin{document}
\leavevmode
\put(0,0){\circle{20.6}}\put(0,0){\color{red}\circle*{20}}

\end{document}

Answer 4

\newcommand\filledcirc{\ensuremath{{\color{red}\bullet}\mathllap{\circ}}} gives you a \circ filled with red color. You need usepackage{mathtools} for the \mathllap command.

To change the border color as well, just change the color of the \circ, like so: \newcommand\filledcirc{\ensuremath{{\color{red}\bullet}\mathllap{\color{blue}\circ}}}.

The advantage over Tikz solutions is that it's much faster.

Answer 5

Put these two lines right after the \begin{document} command:

\setlength{\unitlength}{1mm}

\newcommand{\Newdot}{{\leavevmode\put(0,.63){\circle*{2.5}}}}

Then, anywhere in your document, you can put a big black dot with the \Newdot command.

...
\Newdot
...

This is for black dots. You can adjust the centering with the arguments of the \put(*,*) command, and adjust the size of the dot with the argument of the \circle*(*) command.

Color changes are addressed with \color{*} command as explained in previous comments.