You may use for example:
#action_messageindex board_1 #description_board .category_header {
color: red;
}
for the board title (Allgemein in your second picture), or:
#action_messageindex board_1 .category_header {
color: red;
}
to color anything using category_header in that page.
For the topic titles you can use:
#action_messageindex board_1 .topic_name {
color: red;
}
then, for the topic subject inside the topic itself (picture 3) you can use:
#action_messageindex board_1 #forumposts .category_header {
color: red;
}
or otherwise the more general one:
#action_messageindex board_1 category_header {
color: red;
}
that is the same as the previous for board titles. ![Wink ;)](https://www.elkarte.net/community/smileys/default/wink.svg)
and for the reply numbers:
#action_messageindex board_1 .postarea .keyinfo {
color: red;
}
Of course than you can change the "1" after the id of the board to selectively apply different color schemes to different boards.