background color in titlesec

I am using the titlesec package to format the titles of sections. I would like to change the background color of the frame shape. Concretely, I would like to obtain a solid (that is, the same color for the frame and background) blue frame and white text.

I tried the naive approach of using \colorbox as a format in\titleformat but it does not seem to work:

\documentclass{article}
\usepackage{xcolor}
\usepackage{titlesec}

\setcounter{secnumdepth}{0}

\newcommand{\mybox}[1]{
\colorbox{blue}{\textcolor{white}{#1}}
}

\titleformat{\section}
[frame]
{
\vspace{.8ex}%
\color{blue}\Large\normalfont\sffamily\mybox
}
{\thesection.}
{.5em}
{}

\begin{document}
\section{First section}
The first section begins here\ldots
\section{Second section}
The second section begins here\ldots

\end{document}


I would be very grateful if someone could explain how I can obtain the desired result.

Is it something like this you want?

\documentclass{article}
\usepackage[svgnames]{xcolor}
\usepackage[explicit]{titlesec}

\titleformat{\section}
[display]
{\filcenter
\Large\normalfont\sffamily\color{white}
}
{}
{0pt}
{\colorbox{RoyalBlue!80}{\parbox{\textwidth}{\centering\thesection\strut\\[1ex] #1\vskip 0.5ex}}}

\begin{document}
\section{First section}
The first section begins here\ldots
\section{Second section}
The second section begins here\ldots

\end{document}


• yes, this is the idea, thank you, but without the section numbering (I guess it is enough to change \thesection by \sectionname in the code). I see that you use the option display, so I guess that there is no solid option for frame, right? – suitangi Dec 3 '19 at 11:05
• Not sure what you mean. Unnumbered sections? – Bernard Dec 3 '19 at 11:09
• I have a doubt. Do you want a frame, distinct from the background, but of the same colour? – Bernard Dec 3 '19 at 11:12
• I just don't want the numbers to appear, but this is already fixed changing \thesection by \sectionname in the code. – suitangi Dec 3 '19 at 11:25
• Without the section number, the code should be simpler: use the block style, and as last argument, {\colorbox{RoyalBlue!80}{\parbox{\textwidth}{\centering\strut #1\vskip 0.5ex}}}. On the other hand, the frame is fard-coded in tha package, and I don't see how to patch it to obtain a coloured background. – Bernard Dec 3 '19 at 11:56