I want to produce this particular template in LaTeX. With no page numbering, and rectangles in colours in a a4paper.

I want to produce this particular template in LaTeX. With no page numbering, and rectangles in colours in a a4paper.

Eventhough this question does not show a large amount of effort on your part, you can remove page numbering with \thispagestyle{empty}. To draw the box you desire at the top of the page, you can use TikZ.
\documentclass{book}
\usepackage{tikz}
\usetikzlibrary{calc}
\usepackage{lipsum}
\def\particulartemplate#1{
\thispagestyle{empty}
\begin{tikzpicture}[overlay, remember picture]
\draw let \p1 = (current page.west), \p2 = (current page.east) in
node[minimum width=\x2-\x1, minimum height=2cm, draw, rectangle, fill=blue!20, anchor=north west, align=left, text width=\x2-\x1] at ($(current page.north west)$) {\Large\bfseries \quad #1};
\end{tikzpicture}
}
\begin{document}
\chapter{Chapter one}
\particulartemplate{NATURAL SCIENCES}
\lipsum[1-7]
\end{document}
This will make every page on which you invoke \particulartemplate{Text for box} to be layed out according to your particular template. The example code provided will look like this:

It should be relatively straightforward to modify this code to be a little more flexible. (As in, take the color as an argument, whether or not there should be a border, how the text should be justified, etc.)
PDFTeXify two times, then get the image. But when I compile it under XeLaTeX two times, the "NATURAL SCIENCES" is in the top of the box. Sometimes, XeLaTeX makes a problem.
– Pig Cry
Nov 01 '11 at 14:12
usepackage{atbegshi} and \AtBeginShipout{\AtBeginShipoutUpperLeft{\raisebox{-\height}{\particulartemplate{Natural sciences}}}}
– CPBL
Jul 16 '20 at 17:27
tikzpictureenvironment in the header. – Martin Scharrer Nov 01 '11 at 13:28