short vertical line in footer fancyhdr

Question

I'm having trouble to get the vertical line in the footer shorter. I don't want the line to be pulled through to the bottom of the page. Instead I want it either only the height of the page number or a bit longer like double, the line going also down not up. So either I can define the length or smash, idk please help.

With the geometry package I can get the page number down, but that's not what I want.

\documentclass[12pt, a4paper]{scrreprt}
\usepackage{xcolor}
\usepackage{fancyhdr}
\usepackage{lipsum}
%\usepackage[margin=1in]{geometry}

\fancyhf{}
\fancyfoot[R]{\vfootline\hskip\linepagesep\thepage}
\renewcommand\headrulewidth{0pt}
\newskip\linepagesep \linepagesep 5pt\relax
\def\vfootline{%
   \begingroup\color{blue}\rule[-990pt]{1pt}{1000pt}\endgroup}

\pagestyle{fancy}

\begin{document}
   \lipsum
   \lipsum
   \lipsum
\end{document}

Answer 1

You have to change the options for \rule:

\documentclass[12pt, a4paper]{scrreprt}
\usepackage{lipsum}% only for dummy text
\usepackage{xcolor}
\usepackage{fancyhdr}
\pagestyle{fancy}
\renewcommand\headrulewidth{0pt}
\fancyhf{}
\fancyfoot[R]{\vfootline\hspace{\linepagesep}\thepage}

\newlength\linepagesep
\setlength{\linepagesep}{5pt}
\newcommand*\vfootline{\textcolor{blue}{\rule[-2pt]{1pt}{2\ht\strutbox}}}

\begin{document}
   \lipsum
   \lipsum
   \lipsum
\end{document}

The syntax of \rule is

\rule[<vertical shift>]{<width of the rule>}{<height of the rule>}

If the rule should go down you could use eg.

\rule[-\ht\strutbox]{1pt}{2\ht\strutbox}

---

Remark: You are using a KOMA-Script class. So it is recommended to use package scrlayer-scrpage instead fancyhdr:

\documentclass[12pt, a4paper,twoside,footheight=23pt]{scrreprt}
\usepackage{blindtext}% only for dummy text
\usepackage{xcolor}
\usepackage{scrlayer-scrpage}% sets pagestyle scrheadings automatically
\clearpairofpagestyles
\rofoot*{\vfootline\hspace{\linepagesep}\pagemark}
\lefoot*{\pagemark\hspace{5pt}\vfootline}% for twosided document

\newlength\linepagesep
\setlength{\linepagesep}{5pt}
\newcommand*\vfootline{\textcolor{blue}{\rule[-2pt]{1pt}{2\ht\strutbox}}}

\begin{document}
\blinddocument
\end{document}

Other example:

\documentclass[12pt, a4paper,footlines=2]{scrreprt}
\usepackage{lipsum}% only for dummy text
\usepackage{xcolor}
\definecolor{ultramarineblue}{rgb}{0.25, 0.4, 0.96}

\renewcommand\chaptermarkformat{\chaptername\ \thechapter\autodot\ \ }

\usepackage[automark,headsepline,markcase=upper]{scrlayer-scrpage}
\clearpairofpagestyles
\ohead{\leftmark}
\rofoot*{\vfootline\hspace{\linepagesep}\pagemark}
\lefoot*{\pagemark\hspace{5pt}\vfootline}% for twosided document

\addtokomafont{headsepline}{\color{ultramarineblue}}

\newlength\linepagesep
\setlength{\linepagesep}{5pt}
\newcommand*\vfootline{{\usekomafont{headsepline}\rule[-2pt]{1pt}{2\ht\strutbox}}}

\begin{document}
    \chapter{CTitle}
   \lipsum
    \section{STitle}
   \lipsum
\end{document}

Note that the star in \rofoot* and \lefoot* ensures that page style plain will use the same contents as page style scrheadings. By default chapter pages get page style plain.

Answer 2

Why is it so bad to use fancyhdr? I have some other things I use that I need fancyhdr for. And it works fine. Btw I'm a newbie to Latex.

\documentclass[12pt, a4paper]{scrreprt}
\usepackage{lipsum}% only for dummy text
\usepackage{xcolor}
\usepackage{fancyhdr}
\definecolor{ultramarineblue}{rgb}{0.25, 0.4, 0.96}

\pagestyle{fancy} % Turn on the style
\fancyhf{}
\renewcommand{\headrule}{{\color{ultramarineblue}%
    \hrule width\headwidth height\headrulewidth \vskip-\headrulewidth}}
\renewcommand{\headrulewidth}{0.4pt} 
\fancyhead[R]{\textsl{\leftmark}}
\fancyfoot[R]{\vfootline\hspace{\linepagesep}\thepage}

\fancypagestyle{plain}{%
    \fancyhf{} % clear all header and footer fields
    \fancyfoot[R]{\vfootline\hspace{\linepagesep}\thepage}
    \renewcommand{\headrulewidth}{0pt}
    \renewcommand{\footrulewidth}{0pt}}

\newlength\linepagesep
\setlength{\linepagesep}{5pt}
\newcommand*\vfootline{\textcolor{blue}{\rule[-2pt]{1pt}{2\ht\strutbox}}}

\begin{document}
    \chapter{CTitle}
   \lipsum
    \section{STitle}
   \lipsum
\end{document}