bulma (file, components): fix color fo icons: icons have no color specified anymore for a while, and use the color of parent elements. As they are often used in a `<a>` element (to work without javascript), they are often using a link color. This commit change a few icons to use a dark color instead.

{% extends 'base/base.html' %}

{% block title %}{% trans %}Error {{error_code}}{% endtrans %}{% endblock %}
{% block body %}
{% trans %}An error occured while trying to access the resource.{% endtrans %}
{% endblock body %}
{% block footer %}{% endblock %}