I made a plot but it's not at all what I want. There are two things I'm having trouble with: 1.) The bars should be at the bottom, but there's a space between them and the x-axis. 2.) E1/E4, E2/E5 and E3/E6 should have the same color.
Here's a picture of how it is and how I want it below:

And here's my code:
\documentclass{standalone}
\usepackage{pgfplots,pgfplotstable}
\begin{document}
\begin{tikzpicture}
\begin{axis}[
symbolic x coords={E1, E4 (dyn.), E2, E5 (dyn.), E3, E6 (dyn.)},
xtick=data,
width=\linewidth,
height=6cm
]
\addplot[ybar,fill=blue, bar width = 1cm] coordinates {
(E1, 8)
(E2, 15)
(E3, 50)
(E4 (dyn.), 4)
(E5 (dyn.), 17)
(E6 (dyn.), 40)
};
\end{axis}
\end{tikzpicture}
\end{document}
I hope you can help me. Thanks.