When clicking on one of the galleries the other changes too, what is not meant to be. How can I solve this bug?
Your web page loads the 'juicebox.js' file for each gallery. The 'juicebox.js' file should be loaded only once per page.
Try removing the following line from your second gallery's embedding code:
<script src="../141019_tagderoffenentuer_juicebox/jbcore/juicebox.js"></script>
This should solve your problem.
How it comes that the color of the buttons in the button bar is different to my color setting?
The Juicebox gallery's icons are characters in a custom font and they are inheriting the color from the following code in your 'sakura.css' file:
p, div, h1, h2, h3, h4 {
font-family:"Times New Roman", Times, serif;
font-family: Arial, Helvetica, sans-serif;
font-weight:normal;
font-size:14px;
line-height:140%;
color:#888;
}
Rather than applying these CSS rules to all p, div, h1, h2, h3 and h4 tags on your web page (which will include those within your Juicebox gallery), apply them instead to only those elements which require them through use of ids and classes.