How can I use `\uline` from the `ulem` package to underline text inside a `\colorbox`?

Question

Screenshot:

I have the following code:

\uline{No underlining for \colorbox{lightgray}{everything} inside the colorbox.}

Which looks like this:

How can I get a continuous line for the text inside \colorbox, too?

---

MCVE:

\documentclass[12pt]{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{lmodern}
\usepackage{xcolor}
\usepackage[normalem]{ulem}

\begin{document}

\uline{No underlining for \colorbox{lightgray}{everything} inside the colorbox.}

\end{document}

---

Constraints:

I cannot use soul and I think plain \underline doesn't look very good. (By the way, those who can use soul should have a look at Underline text with background (soul and ulem nesting) )

Answer 1

One way is to underline in a box first:

\documentclass[12pt]{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{lmodern}
\usepackage{xcolor}
\usepackage[normalem]{ulem}


\begin{document}

\sbox0{\uline{\hspace{\fboxsep}everything\hspace{\fboxsep}}}
\uline{No underlining for \colorbox{lightgray}{\hspace{-\fboxsep}\usebox0\hspace{-\fboxsep}} inside the colorbox.}

\end{document}