Steps:
If you don't put # before the color code when changing the 1st or 2nd color used in the forum, the forum will crash. When you go to the home page, you will get an opps... error.
Behavior that should be:
If there is no # at the beginning of the color code, the save button should not be active.
Correction
If you do this and the forum becomes unusable, put # at the beginning of the color code written next to theme_r-primary_color or theme_secondary_color from the database settings table.