@gnaredi : To change the color of the links you will need to add a custom css.
Login to your WordPress admin section. Go to Appearance => Customize => Additional css and add the following css.
a {
color: #color-code;
}
Note: In the above css please change the #color-code with the desired color code that you can find easily on the web.
Regarding the disabling of featured image : login to your WP admin section. Go to Posts section. Edit the desired post and remove the featured image from the particular post and save changes.
Can you please explain in more detail or provide a URL of the post where you want to reduce the height of featured image.
Regards,
Tikaram