\documentclass{article}
\usepackage[usenames,dvipsnames,pdftex]{xcolor}
\usepackage{tikz,ifthen}


\begin{document}
\newcounter{density}
\setcounter{density}{20}
\begin{tikzpicture}
    \def\couleur{MidnightBlue}
    \path[coordinate] (0,0)  coordinate(A)
                ++( 60:12cm) coordinate(B)
                ++(-60:12cm) coordinate(C);
    \draw[fill=\couleur!\thedensity] (A) -- (B) -- (C) -- cycle;
    \foreach \x in {1,...,15}{%
        \pgfmathsetcounter{density}{\thedensity+10}
        \setcounter{density}{\thedensity}
        \path[coordinate] coordinate(X) at (A){};
        \path[coordinate] (A) -- (B) coordinate[pos=.15](A)
                            -- (C) coordinate[pos=.15](B)
                            -- (X) coordinate[pos=.15](C);
        \draw[fill=\couleur!\thedensity] (A)--(B)--(C)--cycle;
    }
\end{tikzpicture}
\end{document}
% Name : RotateTriangle
% Encoding : utf8
% Engine : pdflatex
% Author: Alain Matthes