Hi,
Language can be translated as instructed in the documentation chapter named Translation and Localization in the documentation. Will require you to install the poedit and edit the .po files in the languages folder of the theme.
Edit the .po file using the PoEdit – http://www.poedit.net/. You should be able to locate strings like by, categories, comments etc. and input the corresponding words in dutch.
Regarding the color change, locate the below code in the default.css file at line number 5 and 14 and change the color code
.post-snippets .hentry .entry-title a:hover, ul.post-list .entry-title a:hover { color: #c0442f !important; }
.sidebar li:hover > a { color: #c0442f !important; }