\documentclass[a4paper,12pt]{article}
\usepackage[T1]{fontenc}
\PassOptionsToPackage{defaults=hu-min}{magyar.ldf}
\usepackage[magyar]{babel}

\usepackage{hulipsum}

\usepackage{picture,xcolor,atbegshi}
\AtBeginShipout{%
  \AtBeginShipoutUpperLeft{%
    {\color{blue}%
    \put(\dimexpr 1in+\oddsidemargin,
         -\dimexpr 1in+\topmargin+\headheight+\headsep+\topskip)%
      {%
       \vtop to\dimexpr\vsize+\baselineskip{
         \hrule
         \leaders\vbox to\baselineskip{\hrule width\hsize\vfill}\vfill
       }%
      }%
  }}%
}

\begin{document}

\hulipsum

\end{document}